Module General principles of metabolism Test questions in text form

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Module 2. General principles of metabolism 
Test questions in text form 
1. ______________ is a cosubstrate.
A. * Tetrahydrofolate.
B. NADH
C. Biotin
D. Thiamin pyrophosphate.
E. Pyridoxol phosphate
2. ________________ can bind to the free enzyme.
A. * A competitive inhibitor
B. A uncompetitive inhibitor
C. A non-competitive inhibitor
D. a and c
E. b and c
3. _________ is the coenzyme involved in decarboxylation reactions.
A. Tetrahydrofolate.
B. NADH
C. Biotin
D. Thiamin pyrophosphate.
E. * Pyridoxol phosphate.
4. _____________ alters the Vmax of an enzyme.
A. A competitive inhibitor
B. * A uncompetitive inhibitor
C. A non-competitive inhibitor
D. A and c
E. B and c
5. _____________ binds to the enzyme at sites other than the substrate binding site.
A. An allosteric inhibitor
B. * A uncompetitive inhibitor
C. A non-competitive inhibitor
D. A and c
E. All of the above
6. ____________________ is the term that describes a theoretical value achieved when all 
enzyme substrate binding sites are occupied by the substrate.
A. Km
B. Kcat
C. Vmax
D. * kcat/ Km
E. mg
7. (k-1 + kcat)/k1 = _________.
A. Vmax
B. * Km
C. Kcat
D. Kcat/Km
E. All of the above
8. A catalyst can promote product formation during a chemical reaction by _____.
A. Lowering the activation energy barrier.
B. Stabilizing the transition state.
C. Positioning reactants in the correct orientation.
D. * Bringing reactants together.
E. All of the above

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9. A catalyst can promote product formation during a chemical reaction by _____.
A. Lowering the activation energy barrier.
B. Stabilizing the transition state.
C. Positioning reactants in the correct orientation.
D. * Bringing reactants together.
E. All of the above
10. A column packed with the sieved particles are used in which of the following techniques 
to separate smaller and larger protein molecules
A. Affinity chromatography
B. Electrophoresis
C. * Molecular exclusion chromatography
D. Selective adsorbtion
E. All of these
11. A competitive inhibitor binds to
A. Substrate
B. * Active site
C. Allosteric site
D. Enzyme-substrate complex
E. Coenxyme
12. A reaction is designated as exergonic rather than endergonic when ___________.
A. Activation energy exceeds net energy release
B. Activation energy is necessary
C. No kinetic energy is released
D. * The potential energy of the products is less than the potential energy of the 
reactants
E. It absorbs more energy
13. A reversible inhibitor that can bind to either E alone or the ES complex is referred to as a 
_____.
A. Competitive inhibitor.
B. * Non-competitive inhibitor
C. Uncompetitive inhibitor
D. Suicide inhibitor
E. Irreversible inhibitor
14. A reversible inhibitor that only binds to the ES complex is referred to as a _____.
A. Competitive inhibitor
B. Non-competitive inhibitor
C. Uncompetitive inhibitor
D. Suicide inhibitor
E. * Irreversible inhibitor
15. A thermodynamic pit occurs when
A. ES is not very stable
B. ES forms faster than it dissociates
C. * ES is highly stable
D. S is not bound tightly to an enzyme
E. S is positioned incorrectly to the enzyme
16. According to the second law of thermodynamics, which of the following is true?
A. The total amount of energy in the universe is constant.
B. Energy conversions increase the order in the universe.
C. The ordering of one system depends on the disordering of another.
D. The entropy of the universe is constantly decreasing.
E. * All reactions produce some heat.
17. Active holoenzymes are formed from ____________ in the presence of _________.

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A. Cofactors; proteins
B. Proteins; cofactors
C. * Apoenzymes; cofactors
D. Apoenzymes; proteins
E. Apoenzymes; inactive holoenzymes
18. An allosteric inhibitor of an enzyme usually
A. Binds to the active site.
B. * Participates in feedback regulation.
C. Denatures the enzyme.
D. Causes the enzyme to work faster.
E. Is a hydrophobic compound.
19. An enzyme is said to be catalytically perfect when _______.
A. It has a large Km
B. It has a small kcat
C. * Its kcat/Km value is close to that of the diffusion limit
D. It has very high affinity for the transition state
E. All of the above
20. An enzyme is specific. This means
A. It has a certain amino acid sequence.
B. It is found only in a certain place.
C. It functions only under certain environmental conditions.
D. It speeds up a particular chemical reaction.
E. * It occurs in only one type of cell.
21. An update of Fischer's lock and key theory of enzyme specificity view the _______ as the 
lock and _______ as the key.
A. Enzyme; substrate
B. Substrate; enzyme
C. * Enzyme; transition state
D. Transition state; enzyme
E. Substrate; transition state
22. By efektors can forward some substance, except:
A. Hormones
B. Mediators of the nervous system
C. Metals
D. Products of enzymatic reactions
E. * Vitamins
23. Ca++ or Mg++ are most likely to be part of ___________, while Zn++ or Fe++ are 
present in _______________.
A. * Metal-activated enzymes; metalloenzymes
B. Metalloenzymes; metal-activated enzymes
C. Cofactors; coenzymes
D. Coenzymes; cofactors
E. Apoenzymes; holoenzymes
24. Conserved serine, histidine and aspartate residues are present in the catalytic center of all 
serine proteases. Which of the following describes the role of the histidine residue in the 
mechanism of this reaction?
A. * Covalent binding of acyl groups
B. Hydrophobic stabilization of the substrate
C. Proton transfer
D. Cation binding
E. Anion transport

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25. Consider a hypothetical metabolic pathway for the synthesis of the amino acid arginine: 
precursor A intermediate B arginine. Each reaction is catalyzed by a different enzyme. 
This metabolic pathway is controlled by feedback inhibition with arginine inhibiting the 
conversion of precursor A to intermediate B. In this case, arginine almost certainly acts 
as a _____ of the first enzyme in the pathway.
A. * Substrate
B. Competitive inhibitor
C. Catalyst
D. Cofactor
E. None of the above
26. Covalent modifications that increase the activity of allosterically regulated enzymes do so 
by ______________.
A. * Adding phosphate groups to essential amino acids in the active site
B. Causing the enzyme to fold into a more active configuration
C. Increasing the amount of total enzyme present
D. None of the above
E. All of the above
27. During allosteric, or feed back, inhibition
A. Transcription of mRNA specific for the enzymes involved in the pathway is 
repressed by the pathway's end product.
B. Enzyme concentrations in the cell remain relatively constant.
C. * The pathway's end product represses the activity of the first enzyme in the 
pathway
D. All of the above apply to feedback inhibition.
E. More than one of the above, but not all, apply to feedback inhibition.
28. During electrophoretic research of LDG in the blood serum found out predominance of 
content of LDG1 and LDG2. Pathology of what organ does these information testify?
A. Lungs
B. * Heart
C. Liver
D. Musculs
E. Spleen
29. During enzyme repression
A. The pathway's end product represses the activity of the first enzyme in the 
pathway.
B. B.Enzyme concentrations in the cell remain relatively constant.
C. Transcription of mRNA specific for the enzymes involved in the pathway is 
repressed by the pathway's end product.
D. * More than one of the above, but not all, apply to feedback inhibition.
E. All of the above apply to feedback inhibition.
30. During feedback inhibition, the effector molecule binds to the enzyme's ___________ 
site
A. Permissive
B. Alternative
C. Allosteric
D. * Conformational
E. Active
31. Energy-requiring reactions can occur in biological systems because enzymes allow their 
coupling to other reactions with:
A. The activation energy of the reaction is doubled.
B. The activation energy of the reaction is lowered.
C. It's optimal conditions for temperature of the enzyme are doubled.

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D. * The shape of the enzyme molecule is changed.
E. All of above
32. Enzymes that are allosterically regulated ____________________.
A. Are multimeric proteins
B. * Possess regulatory and catalytic domains
C. Do not behave according to the Michaelis-Menton equation
D. All of the above
E. Are monomeric proteins
33. Enzymes:
A. Are composed primarily of polypeptides, which are polymers of amino acids.
B. * Can bind prosthetic groups such as metal ions that participate in enzyme 
reactions.
C. Have defined structures.
D. Bind their substrates at active sites.
E. All statements are true.
34. Ethanol (CH3CH2OH) is the alcohol found in beverages. It is oxidized in the body to 
acetaldehyde by the enzyme alcohol dehydrogenase. Methanol (CH3OH), also known as 
wood alcohol, is converted to formaldehyde by the same enzyme. Acetaldehyde is toxic, 
but formaldehyde is far more toxic to humans, which is why the ingestion of relatively 
small amounts of methanol can cause blindness or death. One treatment for mild 
methanol poisoning is the administration of ethanol. Why might a doctor choose this 
treatment?
A. Ethanol must act as a competitive inhibitor for the alcohol dehydrogenase and 
therefore slows the formation of formaldehyde.
B. Ethanol likely irreversibly binds to alcohol dehydrogenase which prevents the 
formation of formaldehyde.
C. * The ethanol is likely an uncompetitive inhibitor and binds to a site other than 
the active site of the enzyme.
D. The doctor has given up on the patient and administers ethanol for sedation
E. B and C
35. If it is known that the only two ionizable residues in the active site are both glutamates, 
which conclusion can be drawn?
A. * The glutamates have different microenviroments which cause their pKa's to 
differ.
B. One of the glutamates must be amidated.
C. Both glutamates have a pKa equal to 5.0.
D. Both glutamates are deprotonated during the reaction.
E. B and C
36. If the tertiary structure of an enzyme is changed _____.
A. * Its substrate may not fit properly in the active site
B. It will be missing one of its polypeptides
C. The helical coil will be stretched out
D. The product of the reaction will be a different molecule
E. Its substrate will bond covalently with the wrong part of the molecule
37. In a multienzyme complex the process of directly transferring a product of one reaction 
to the next active site without allowing it to enter the bulk solvent is termed _______.
A. a ping-pong reaction
B. * metabolite channeling
C. the activity pathway
D. the sequential mode
E. All of the above
38. In a ping-pong reaction which does not occur?

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A. One product is released before a second substrate is bound.
B. The enzyme covalently binds a portion of the first substrate.
C. * The enzyme is permanently converted to an altered form by the first substrate.
D. A group is transferred from one substrate to another.
E. All of the above
39. Izoenzymes differ between itself some physical and chemical properties, except:
A. Electrophoretic mobility
B. Molecular activity
C. Stability
D. * Present in different tissues
E. Difference their primary structure
40. Mg2+ is used as a(n) by metal activate enzymes that utilize negatively charged substrates 
like ATP.
A. Metalloenzyme
B. * Activator ion
C. Prosthetic group
D. Co-substrate
E. Ingibitor ion
41. R-CH2OH + O2 > R-CHO + H2O2 which of the following types of enzymes catalyzes 
this reaction
A. Dehydrogenase
B. Oxidase
C. * Peroxidase
D. Aldolase
E. Catalase
42. Some antibody molecules are enzymatic if they are formed against
A. Enzymes
B. Enzymes bound to other proteins
C. * Transition state analogs bound to other proteins
D. Transition state analogs
E. All of the above
43. Specificity of enzyms is conditioned by the following factors, except:
A. Conformation complementare
B. Electrostatic complementare
C. The feature structure of active center of enzyme
D. * The feature structure of allosteric center
E. Proteins nature
44. ?The active site of an enzyme differs from an antibody-antigen binding site in that the 
enzyme active site
A. Contains modified amino acids
B. Catalyzes a chemical reaction
C. Is complementary to a specific ligand
D. * Contains amino acids without sidechains
E. None of the above are correct
45. The assumptions made in calculating the Michaelis-Menten Equation include
A. That the formation and decomposition of ES is the same for a period of time
B. That the concentration of the substrate is much greater than the concentration of E
C. That the value of k-2 can be ignored
D. * a, b and c
E. a and b
46. The catalytic triad of chymotrypsin and other serine proteases are
A. Three subunits of the enzyme.

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B. Three adjacent amino acid residues which act to make serine a strong nucleophile.
C. * Three amino acid residues close enough together to make serine a strong 
nucleophile.
D. Three enzymes with very similar structural features.
E. All of the above
47. The concentrations of enzymes is determined by using pseudo first-order conditions in 
which
A. S concentration is kept the same and the rate is measured
B. E concentration is kept the same and the rate is measured
C. * S concentration is constant, E concentration varied and the rate is measured
D. E concentration is constant, S concentration varied and the rate is measured
E. All of the above
48. The data shown on the graph were obtained for a kinetic experiment. What type of 
inhibition is it?
A. Competitive
B. Uncompetitive
C. * Noncompetitive
D. Irreversible
E. A and B
49. The enzyme has an active site which
A. Fits the substrate exactly
B. Fits the transition state
C. May contain hydrogen bonds which are covalent like
D. a and c
E. * b and c
50. The equilibrium constant for the reaction, glucose 6-phosphate + water T glucose + 
phosphate, is 260. What can you conclude about this reaction:
A. It is a closed system
B. It never reached equilibrium.
C. Starting with glucose 6-phosphate, it is not spontaneous.
D. * At equilibrium, the concentration of glucose is much higher than the 
concentrations of glucose 6-phosphate.
E. At equilibrium, the concentration of glucose is much higher than the 
concentrations of phosphate
51. The mechanism of enzyme action is _____.
A. * To create an energy barrier between substrates
B. To lower the energy of the activation of a reaction
C. To change the direction of thermodynamic equilibrium
D. To change endergonic into exergonic reactions
E. To allow substrates to move more freely in solution
52. The Michaelis constant, Km, is
A. The maximum velocity that any given enzyme reaction can achieve
B. The substrate concentration which gives the best enzyme assay for an enzyme 
reaction
C. * The substrate concentration when the reaction is half the way toward the 
maximal velocity
D. The maximal velocity divided in half
E. All of the above
53. The rate of a second order reaction depends on the concentration of _________.
A. One substrate
B. * Two substrates
C. Three substrates

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D. None of the above
E. Ten substrates
54. The result of a(n) __________ reaction is that energy is released. Energy must be added 
for a(n) __________ reaction to proceed.
A. Enzyme catalyzed, non-spontaneous
B. * Exergonic, endergonic
C. Endergonic, spontaneous
D. Catalytic, non-catalytic
E. Oxidative, hydrolysis
55. The steady state assumption for Michaelis-Menton kinetics assumes that ______.
A. * The concentration of the ES complex is constant
B. The rate of ES formation is faster than the rate of ES disassociation
C. k1 = k-1= kcat
D. The concentration of the ES complex is increase
E. None of the above
56. The term ligase refers to a class of enzymes that catalyzes_________.
A. Oxidation reduction reactions
B. Reactions involving the transfer of a functional group from one molecule to 
another
C. Hydrolytic cleavages
D. * Reactions where two molecules are joined together
E. All of the above
57. The time that is required for an enzyme to convert one substrate molecule into one 
product molecule is
A. Km
B. kcat
C. 1/Km
D. * 1/kcat
E. 1 min
58. The Vmax of an enzyme changes when the enzyme is treated with a_____.
A. Competitive inhibitor
B. Uncompetitive inhibitor
C. Noncompetitive inhibitor
D. A and b
E. * B and c
59. Two curves showing the rate versus substrate concentration are shown below for an 
enzyme-catalyzed reaction. One curve is for the reaction in the presence of substance X. 
The other curve is for data in the absence of substance X. Examine the curves and tell 
which statement below is false.
A. X is an activator of the enzyme.
B. The enzyme kinetics are non-Michaelis-Menton.
C. X is likely an allosteric modulator.
D. * X is a competitive inhibitor.
E. None of above
60. What shape would a graph of reaction velocity versus pH have for an enzyme that uses 
both a proton donor and a proton acceptor during catalysis (both acid and base catalysis)?
A. Sigmoidal
B. Hyperbolic
C. Exponential
D. * Bell-shaped
E. Linear

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61. When the concentration of a substrate inside a cell falls below the substrate concentration 
at half maximal velocity,
A. ES is formed more easily
B. * ES dissociates to E + S
C. ES is closer to the ground state than to the transition state
D. E + S is in equilibrium with ES
E. The reaction will not proceed
62. When the rate of an enzymatic reaction is controlled by the amount of enzyme present, 
which of the following factors controls enzyme levels?
A. Rates of transcription
B. Rates of translation
C. Rates of protein turnover
D. Rates of mRNA turnover
E. * All of the above
63. Which cofactor has the following properties: a) forms Schiff base, b) its precursor is 
absorb dietarily as Vitamin B6, c) is required in a number of reactions in aminoacid 
metabolism.
A. Thiamin pyrophosphate
B. Biotin
C. Lipoamide
D. * Pyridoxal phosphate
E. Nicotinamid
64. Which from the adopted enzymes can united in polienzymes complexes?
A. * Pyruvatdehydrogenase
B. Transketolase
C. Suktsinatdehydrogenase
D. Al'dolase
E. Glukos-6-phosphatase
65. Which is not a reason for metabolite channeling?
A. Protection of intermediates from degradation.
B. Increasing the overall rate of a reaction.
C. Producing locally high concentrations of intermediates.
D. * Ensuring the enzyme is properly regulated.
E. A and C
66. Which of the following are properties of a cosubstrate?
A. * They are covalently attached to the active site of the enzyme.
B. Once they have been involved in an enzymatic reaction require a separate 
unrelated enzymatic reaction to be converted to their original state.
C. They remain unchanged over the course of a reaction.
D. B and c
E. All of the above.
67. Which of the following coenzymes forms a Schiff’s base during catalysis?
A. NADH
B. Thiamin pyrophosphate
C. Lipoamide
D. * Pyridoxal phosphate
E. Coenzyme A
68. Which of the following cofactors is able to bind CO2 and transfer it to an appropriate 
acceptor molecule?
A. * Pyridoxal phosphate
B. Biotin
C. Thiamin pyrophophosphate

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D. Lipoamide
E. NAD(P)H
69. Which of the following common drugs is not a specific enzyme inhibitor?
A. Methotrexate
B. Penicillin
C. * Sulfonilamide
D. Iodine
E. Viagra
70. Which of the following factors contribute to the elevation of the ground state energy of a 
substrate once it binds to the enzyme?
A. Less favorable entrophy values
B. Favorable charge-charge interactions
C. * Interactions between polar functional groups on the substrate surface and 
hydrophobic amino acids in the enzyme’s substrate binding site.
D. A and b
E. A and c
71. Which of the following is characteristic of an enzyme catalyst?
A. It positions reactants in the correct orientation
B. It lowers the activation energy barrier
C. It binds the transition state tighter than the substrate
D. * Are affected by temperature
E. All of the above
72. Which of the following is true for a covalent catalysis based enzymatic mechanism.
A. A covalently modified enzyme intermediate is involved.
B. The enzyme undergoes a sequential reaction.
C. The enzyme undergoes a ping pong reaction.
D. a and b
E. * a and c
73. Which of the following kinetic parameters best describes how well suited a specific 
compound functions as a substrate for a particular enzyme?
A. Km
B. Vmax
C. kcat
D. * kcat/Km
E. kg
74. Which of the following reversible inhibitors alter an enzyme’s function by increasing the 
Vmax of the enzyme?
A. Competitive inhibitor
B. Non-competitive inhibitor
C. Uncompetitive inhibitor
D. * None of the above
E. Over-competitive inhibitor
75. Which of the following statements about reaction rate is NOT true?
A. Reaction rate is the speed at which the reaction proceeds toward equilibrium.
B. Reaction rate is governed by the energy barrier between reactions and products
C. * Enzymes can accelerate the rate of a reaction.
D. Reaction rates are not sensitive to temperature.
E. None of these.
76. Which property is common for enzymes and inorganic catalysts?
A. Specificity
B. Sensitiveness to the action of extraneous factors
C. * Catalysis only thermodynamics possible reactions

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D. Dependence from рН and temperatures
E. High catalytic activity
77. Which statement is false about allosteric regulation?
A. * It is usually the mode of regulation for the last step in reaction pathways since 
this step produces the final product.
B. Cellular response is faster with allosteric control than by controlling enzyme 
concentration in the cell.
C. The regulation usually is important to the conservation of energy and materials in 
cells.
D. Allosteric modulators bind non-covalently at sites other than the active site and 
induce conformational changes in the enzyme.
E. B and C
78. Which statement is false about covalent modification?
A. It is reversible.
B. It is slightly slower than allosteric regulation.
C. * It usually uses the same enzyme for activation and inactivation.
D. All of the above
E. A and B
79. Which statement is false about regulatory enzymes that are controlled allosterically?
A. * They are always less active when a modulator is bound to them.
B. They are often larger than other enzymes.
C. They have more than one binding site.
D. They often catalyze the first step in a reaction pathway.
E. They have more than two binding site.
80. Why does heating interfere with the activity of an enzyme?
A. It kills the enzyme.
B. It changes the enzyme’s shape.
C. It decreases the energy of substrate molecules.
D. * It causes the enzyme to break up.
E. It decreases the chance that the enzyme will meet a substrate molecule.
81. Zymogens are inactive enzyme precursors which are made active by
A. A change in structure
B. Selective proteolysis
C. Secretion to new types of cells
D. a and b
E. * a, b and c
82. Which element is present in maltase, but not in maltose?
A. Carbon
B. Hydrogen
C. Oxygen
D. * Nitrogen
E. None of the above
83. _________ is the coenzyme involved in decarboxylation reactions.
A. Tetrahydrofolate.
B. NADH
C. Biotin
D. Thiamin pyrophosphate.
E. * Pyridoxol phosphate.
84. A certain enzyme will hydrolyze egg white but not starch. Which statement best explains 
this observation?
A. Starch molecules are too large to be hydrolyzed.
B. * Enzyme molecules are specific in their actions.

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C. Egg white acts as a coenzyme for hydrolysis.
D. Starch is composed of amino acids.
E. Egg white acts as a inhibitor for hydrolysis.
85. A coenzyme is
A. An ionic cofactor that interacts with an enzyme to allow it to work.
B. A protein cofactor that interacts with an enzyme to allow it to work.
C. * A nonprotein organic cofactor that interacts with an enzyme to allow it to work.
D. An ionic cofactor that interacts with an enzyme to inhibit it.
E. A protein cofactor that interacts with an enzyme to inhibit it.
86. A competitive inhibitor binds to
A. Substrate
B. * Active site
C. Allosteric site
D. Enzyme-substrate complex
E. Coenxyme
87. A competitive inhibitor of an enzyme is usually:
A. A highly reactive compound.
B. A metal ion such as Hg2+ or Pb2+.
C. * Structurally similar to the substrate.
D. Water insoluble.
E. A poison.
88. A laboratory test allows assuming the presence of inflammatory process in a liver. The 
increase of what enzyme in blood will confirm this?
A. LDH 1,2
B. * Carbamoil phosphate ornitin transferase
C. AsAT
D. Creatin phosphokinase
E. Aldolase
89. A newborn suffers convulsions after meal, touches. It is discovered that reason of disease 
is a defect of pyridine dependent enzyme which forms GABA in a brain. Name this 
enzyme.
A. * Glutamate decarboxylase
B. Amino transferase
C. Cistationin synthase
D. Kinurinase
E. Ribonuclease
90. A phenylketonuria appears as a result of innate absence of enzyme:
A. Tirosin oxidase
B. * Phenylalanin-4-hydroxylase
C. Oxidase of gomogentisic acid
D. Amino oxidase
E. Xantine oxidase
91. A reversible inhibitor that can bind to either E alone or the ES complex is referred to as a 
_____.
A. Competitive inhibitor.
B. * Non-competitive inhibitor
C. Uncompetitive inhibitor
D. Suicide inhibitor
E. Irreversible inhibitor
92. A reversible inhibitor that only binds to the ES complex is referred to as a _____.
A. Competitive inhibitor
B. Non-competitive inhibitor

---

C. Uncompetitive inhibitor
D. Suicide inhibitor
E. * Irreversible inhibitor
93. A substance that is Not a coenzyme is
A. * ATP
B. NAD+
C. NADPH
D. FAD
E. Pyrydoxal phosphate
94. Abzymes are
A. Immuno globulins
B. Isozymes
C. * Allosteric enzymes
D. Catalytic antibodies
E. Vitamins
95. According to the international classification there are six classes of enzymes in such 
order:
A. Oxidoreductases, hydrolyses, ligases, lyases, transferases, isomerases.
B. Transferases, hydrolyses, oxidoreductase, isomerases, lyases, ligases.
C. Hydrolyses, oxidoreductase, transferases, lyases, isomerases, ligases.
D. Oxidoreductase, transferases, hydrolyses, isomerases, ligases, lyases.
E. * Oxidoreductase, transferases, hydrolyses, lyases, isomerases, ligases.
96. Active trypsin formation by the action of enteropeptidase can be viewed as the master 
activation step because
A. It occurs first
B. It can activate its own zymogen
C. * Trypsin activates other pancreatic zymogens
D. A and B
E. A, B and C
97. Acyl-group-transfer reactions often involve which coenzyme?
A. * Coenzyme A
B. NAD+
C. Cytochrome c
D. All of the above
E. None of the above
98. Aldolase is classified as a(n)
A. Oxidoreductase
B. Transferase
C. Hydrolase
D. * Lyase
E. Isomerase
99. Allosteric centers serve as:
A. * The place of influence on the enzyme different regulator factors
B. The place of enzyme and substrate relation
C. Catalytic area
D. Contact area
E. All of the above
100. 
Allosteric enzymes _____________.
A. Usually have quaternary structure.
B. Do not behave according to Michaelis-Menten kinetics.
C. * Bind allosteric modulators at sites not associated with substrate binding.
D. Often have separate catalytic and regulator domains.

---

E. All of the above.
101. 
Among the below named enzymes a metalloprotein is following:
A. * Carboanhydrase
B. Lactate dehydrogenase
C. Pepsin
D. Phosphatase
E. Amylase
102. 
Among the enzymes of antioxide defense of an organism directly decomposes the 
toxic hydrogen peroxide:
A. * Catalase
B. Superoxyde dismutase
C. Glutation peroxidase
D. Glutation reductase
E. Xantine oxidase.
103. 
An enzyme is generally named by adding ____ to the end of the name of the 
_____.
A. "-ose". cell in which it is found
B. "-ase". cell in which it is found
C. "-ose". substrate
D. * "-ase". substrate
E. "-ase". coenzyme
104. 
An enzyme that catalyzes conversions of L-sugars to D-sugars is called an
A. Lyase
B. Hydrolase
C. Synthetase
D. Synthase
E. * Isomerase
105. 
An enzyme that hydrolyzes protein will not act upon starch. This fact is an 
indication that enzymes are
A. Hydrolytic
B. * Specific
C. Catalytic
D. Synthetic
E. Universal
106. 
An increase of acetaldehyde in blood is causes disgust of an alcohol. What 
preparation - the inhibitor of aldehyde dehydrogenase is used in medical practice for the 
prophylaxis of alcoholism?
A. Ethanol.
B. * Teturam.
C. Trasilol
D. Aldehyde.
E. Methanol.
107. 
An inhibitor binds to a site other than the active site of the enzyme. Which 
statement below correlates with this observation?
A. It must be a competitive inhibitor.
B. The inhibition must be irreversible.
C. * It could be noncompetitive or uncompetitive inhibition.
D. It could be irreversible, competitive, noncompetitive or uncompetitive. The data 
do not relate to the type of inhibition.
E. None of above
108. 
An inhibitor that changes the overall shape and chemistry of an enzyme is known 
as a(n)

---

A. * allosteric inhibitor
B. competitive inhibitor
C. steric inhibitor
D. noncompetitive inhibitor
E. None of the above.
109. 
An ion commonly found in metalloenzymes and which can undergo reversible 
oxidation and reduction is
A. Ca++
B. Mg++
C. S=
D. * Fe++
E. All of the above
110. 
An uncompetitive inhibitor of an enzyme catalyzed reaction
A. * Binds to the Michaelis complex (ES).
B. Decreases Vmax.
C. Is without effect at saturating substrate concentration.
D. Can actually increase reaction velocity in rare cases.
E. The first and second choices are both correct.
111. 
An update of Fischer's lock and key theory of enzyme specificity view the 
_______ as the lock and _______ as the key.
A. * Enzyme; substrate
B. Substrate; enzyme
C. Enzyme; transition state
D. Transition state; enzyme
E. Substrate; transition state
112. 
At 25 C. the optimum reaction rate of a certain enzyme occurs at a pH of 7. A 
greater reaction rate could probably be attained by
A. * Increasing the temperature to 35 C and keeping the pH at 7
B. Increasing both the temperature and the pH
C. Decreasing the pH and increasing the temperature
D. Increasing the pH and keeping the temperature at 25 C.
E. All of the above
113. 
At a blood test was set that activity of catalase is 5 units. It is a symptom of:
A. Hypoxia
B. Acidosis
C. * Anemia
D. Starvations
E. Diabetes mellitus
114. 
At about 0 C., most enzymes are
A. * Inactive
B. Active
C. Destroyed
D. Replicated
E. Denaturated
115. 
At hepatitis, heart attack in blood of patients activity of alanine- and aspartate 
amino transferases sharply grow. What reasons of activation of these enzymes in blood?
A. An increase of intensity of disintegration of amino acid in tissues
B. Activation of amino acids synthesis in tissues
C. Activation of enzymes with hormones
D. * Damage of cells membranes and output of enzymes in blood
E. Lack of pyridoxine

---

116. 
At high temperatures, the rate of enzyme action decreases because the increased 
heat
A. Changes the pH of the system
B. * Alters the active site of the enzyme
C. Neutralizes the acids and bases in the system
D. Increases the concentration of the enzyme
117. 
At parodontitis the secretion of kallikrein is increased. Choose, what strengtheners 
of inflammatory reaction appear in an oral cavity as result the of this enzyme action?
A. Trasilol
B. * Kinins
C. Secretory immunoproteins
D. Lysozyme
E. Factor of nerves growth
118. 
At the heart attack in blood of a patient were found out increase of enzymes 
activity. Choose these enzymes:
A. * Creatin kinase, AsAT and LDH1,2
B. Mono amino oxidase
C. Cytochrome oxidase, AlAT
D. Carbo anhydrase
E. Lactate dehydrogenase
119. 
Ca++ or Mg++ are most likely to be part of ___________, while Zn++ or Fe++ 
are present in _______________.
A. * Metal-activated enzymes; metalloenzymes
B. Metalloenzymes; metal-activated enzymes
C. Cofactors; coenzymes
D. Coenzymes; cofactors
E. Apoenzymes; holoenzymes
120. 
Catalase is found in all cells and protects them from a dangerous waste chemical 
by breaking it down into water and oxygen. What is this waste chemical?
A. * Hydrogen Peroxide
B. Nitrogen Dioxide
C. Lactic Acid
D. Carbon Monoxide
E. Urea
121. 
Choose the enzyme which includes zinc?
A. * Alcohol dehydrogenase
B. Cytochromoxidase
C. Xantine oksidase
D. Pyruvate dehydrogenase
E. Lactate dehydrogenase
122. 
Determination of amylase in blood can be diagnostic criteria for:
A. Nephritis
B. Glossitis
C. * Acute pancreatitis
D. Hepatitis
E. Anemia
123. 
During a gastric secretion proteolytic enzymes are secreted as proenzymes. What 
enzyme is activated with hydrochloric acid:
A. * Pepsinogen
B. Trypsinogen
C. Amylase
D. Lipase

---

E. Chymotrypsinogen
124. 
Enzymes
A. Enhance reaction rate
B. Are affected by pH
C. Act on specific substrates
D. Are affected by temperature
E. * All of the above
125. 
Enzymes catalyze transfer of structural fragments from one substrate to other with 
formation of two products. Name the class of this enzyme.
A. * Transferase
B. Isomerase
C. Oxidoreductase
D. Ligase
E. Hydrolase
126. 
Enzymes fast up the velocity of a biochemical reaction by
A. Increasing activation energy
B. Decreasing kinetic energy
C. Removing the functional group
D. * Decreasing activation energy
E. All of the above
127. 
Enzymes influence chemical reactions in living systems by
A. Providing the substrate required for the reaction to occur
B. * Affecting the rate at which reactions occur
C. Absorbing water released when polymers are formed
D. Combining with excess hydrogen to form gaseous wastes
E. Increasing activation energy
128. 
Enzymes of which class are responsible for transfer of structural fragment from 
one substrate to other with formation of two products?
A. Oxidoreductases
B. Isomerases
C. * Transferases
D. Ligases
E. Hydrolases
129. 
Enzymes that are activated by proteolytic cleavage are referred to as __________.
A. Covalently modified enzymes
B. Enzyme complexes
C. * Zymogens
D. Polymerized
E. Free radicals
130. 
For a diet therapy at indigestion of milk for children used milk with diminish 
maintenance of lactose with fermentative way. What enzyme is used for this aim?
A. * beta-galactosidase
B. beta-glycosidase
C. alpha- glycosidase
D. alpha-amilase
E. beta- amilase
131. 
For diminishing of a patient’s depression used preparation, which inhibits 
enzyme, catalyzing decomposition of biogenic amines. Name this enzyme:
A. * MAO (mono amino oxidase)
B. LDH (lactate dehydrogenase)
C. CPK (creatin phosphokinase )
D. ASAT (aspartate amino transferase)

---

E. ALAT (alanine amino transferase)
132. 
For dissolving of scars, compressions, hematomas, the easier transport of 
medications in tissues such enzyme is used:
A. Trypsin
B. Ribonuclease
C. * Hyaluronidase
D. Plasmin
E. Pepsin
133. 
For prevention of intestine atony the competitive inhibitor of acetylcholine 
esterase is recommended for a patient. Choose it:
A. * Prozerin
B. Aspirin
C. Zarin
D. Indometocin
E. Allopurinol
134. 
For treatment of viral infections it is used such enzyme preparation:
A. Plasmin
B. Collagenase
C. Lizocym
D. Hyaluronidase
E. * DNA-ase, RNA-ase.
135. 
From the human blood serum selected five isoenzyme forms which catalyze the 
same reaction.Choose this enzyme:
A. Glutathione reductase
B. Ceruloplasmin
C. * Lactate dehydrogenase
D. Glucose-6-phosphate dehydrogenase
E. Superoxide dismutase
136. 
Glucose + ATP > Glucose -6-phosphate + ADP. This reaction is catalysed by 
which of the following enzyme classes
A. Oxidoreductase
B. * Transferase
C. Hydrolase
D. Lyase
E. Isomerases
137. 
Glycoside hydrolases such as bacterial cellulase have been shown to differ in 
mechanisms from that of lysozyme. They
A. Are alkaline catalysts
B. Form a boat form of the sugar
C. * Form a covalent sugar-enzyme intermediate
D. Do not distort the substrate
E. Have no active site side chain interactions
138. 
How is nonprotein part of enzyme called?
A. Holoenzyme.
B. Apoenzyme.
C. * Cofactor.
D. Apoprotein.
E. None of the above
139. 
How many active centers can have enzymes?
A. 1
B. 3
C. 2

---

D. * Depends on the amount of subunits of enzyme
E. 10
140. 
How many classes of enzymes are there?
A. 4.
B. 5.
C. * 6.
D. 7.
E. 2
141. 
In a multienzyme complex the process of directly transferring a product of one 
reaction to the next active site without allowing it to enter the bulk solvent is termed 
_______.
A. a ping-pong reaction
B. * metabolite channeling
C. the activity pathway
D. the sequential mode
E. All of the above
142. 
In an organism was found the lack of copper. It will cause the decrease of such 
enzyme activity:
A. Cytochrome b
B. Glucose oxidase
C. Catalase
D. * Cytochrome oxsidase
E. Glutation peroxidase
143. 
In an organism was found the lack of iron. It will cause the decrease of such 
enzyme activity:
A. Glutation peroxidase
B. Carboanhydrase
C. Carboxypeptidase
D. Ceruloplasmin
E. * Catalase
144. 
In blood of patient found out the increase of activity of LDH 4,5, AlAT, carbamoil 
ornitin transpherase. In which organ is it possible development of pathological process?
A. * In a liver (hepatitis is possible)
B. In a cardiac muscle (the heart attack of myocardium is possible)
C. In skeletal muscles
D. In kidneys
E. In connecting tissue
145. 
In diagnostics of heart attack an important role belongs to the methods of 
enzymodiagnostic. Determination of what enzyme level in blood of in the first 2-4 hours 
after sharp pain is important for diagnostic?
A. * Creatin phosphokinase
B. Acetylcholine esterase
C. Lipoprotein lipase
D. Alanine amino transferase
E. Aldolase
146. 
In enzyme controlled reactions, the role of certain vitamins such as niacin is to act 
as
A. An enzyme
B. A substrate
C. * A coenzyme
D. A polypeptide
E. An allosteric centre

---

147. 
In formation of temporal complex between an enzyme and substrate important 
role belongs to chemical bonds, except:
A. Disulfide
B. Ion
C. * Peptid
D. Hydrogen bonds
E. Hydrophobic interaction
148. 
In saliva there is an enzyme which has a strong bactericide action due to ability to 
destroy 1-4 glycoside bonds of peptide-glycans of bacterial wall. Choose this enzyme:
A. Amylase
B. * Lizocim (muramidase)
C. Trypsin
D. Phosphatase
E. Ribonuclease
149. 
In the human organism single-electron reduction of molecular oxygen superoxide, 
hydroxyl radicals and hydrogen peroxide, which have high reactional ability appear 
constantly. A hydrogen peroxide inactivated in an organism with:
A. Ceruloplasmin
B. * Catalase
C. Glutathione reductase
D. Glucose-6-phosphatedehydrogenase
E. Superoxide dismutase
150. 
Induced fit studies by Koshland using the enzyme hexokinase showed that there 
are enzyme forms
A. which react with the hydroxyl group of water
B. which react only with ATP and glucose present together
C. which are hydrophobic, excluding the competing hydroxyl group from water
D. * with and without glucose bound to each
E. that hydrolyze AT
151. 
is known as _________ inhibition.
A. * Competitive
B. Uncompetitive
C. Uncompetitive
D. Feedback
E. Allosteric
152. 
Isoenzymes are generally separated by
A. Ion exchange chromatography
B. Gel filtration chromatography
C. Paper chromatography
D. * Electrophoresis
E. Selective adsorbtion
153. 
Izoenzymes differ between itself some physical and chemical properties, except:
A. Electrophoretic mobility
B. * Molecular activity
C. Stability
D. Present in different tissues
E. Different primary structure
154. 
Km is _______.
A. The substrate concentration at ? Vmax.
B. = (k-1 + kcat)/k1
C. Related to an enzymes affinity for a specific substrate.
D. The Michaelis Constant

---

E. * All of the above
155. 
Lactate + NAD+ ---> Pyruvate + NADH + H+
A. * Oxidoreductase
B. Transferase
C. Hydrolase
D. Lyase
E. Ligase
156. 
Lactate dehydrogenase is a
A. Coenzyme
B. * Isoenzyme
C. Zymogen
D. Abzyme
E. Prostetic group
157. 
Lipase, maltase, and protease are members of a group of compounds known as
A. Hormones
B. Carbohydrates
C. Lipids
D. * Enzymes
E. Coenzymes
158. 
Lock and key theory was proposed by
A. Sumner
B. * Fischer
C. Sanger
D. Buchner
E. Michaelis
159. 
Lyzocym is a antibacterial factor, muraminidase as a mechanism of action (splits 
1-4 glycoside bonds of muramine). What class of enzymes does it belong to?
A. Transferases
B. Oxidoreductases
C. Lyases
D. Isomerases
E. * Hydrolases
160. 
Mg2+ is used as a(n) _________ by metal activate enzymes that utilize negatively 
charged substrates like ATP.
A. Metalloenzyme
B. * Activator ion
C. Prosthetic group
D. Co-substrate
E. Ingibitor ion
161. 
NAD+, FAD, and FMN are all cofactors for:
A. * Oxidoreductases
B. Transferases
C. Hydrolases
D. Lyases
E. Ligases
162. 
Name laboratory tests which should be conducted for the patients with suspicion 
on a acute pancreatitis:
A. total blood test
B. Activity of LDH
C. Activity of AlAT
D. * Activity of amylase in urine and blood
E. A level of sugar in blood

---

163. 
New antibiotics are synthesized with fermentative transformations of natural 
antibiotics. What from the below named forms of enzymes are widely used in 
pharmaceutical industry?
A. * Immobilized enzymes
B. Native enzymes
C. Denaturized enzymes
D. Complex of enzyme with a coenzyme
E. Complex of enzyme with an activator
164. 
Noncompetitive inhibitor binds with
A. Active site
B. Allosteric site
C. Enzyme substrate complex
D. * Substrate
E. Product of reaction
165. 
One of major enzymes of saliva, providing death of bacteria is:
A. * Lysozyme
B. LDH
C. Phosphatase
D. AsAT
E. AlAT
166. 
Oxidases, peroxidases, oxygenases or reductases are all
A. Lyases
B. Synthases
C. Synthetases
D. * Oxidoreductases
E. Hydrolases
167. 
Phenylketonuria of newborn may be diagnosed after a reaction of urine with:
A. * FeCI3
B. CuSO4
C. NaCl
D. Fe+
E. Na3PO4
168. 
Prosthetic group of cytochrome is:
A. FAD
B. Ubiqinon
C. Biotin
D. * Iron porphyryn complex
E. Cooper contain porphyryn complex
169. 
Pyridoxal phosphate is involved in which type of reaction?
A. oxidation of pyruvate
B. * production of new amino acids by transamination
C. phosphate-transfer to produce ATP from ADP
D. the regeneration of methionine from homocysteine
E. none of the above
170. 
Pyruvate + H+ ---> Acetaldhyde + Carbon dioxide
A. Oxidoreductase
B. Transferase
C. Hydrolase
D. * Lyase
E. Ligase

---

171. 
Pyruvate dehydrogenase complex is a multi-enzyme complex that catalyzes a 
complicated multi-step reaction. The final reaction step is : FADH2 + NAD+ > FAD + 
NADH + H+ The final step of this reaction falls into which enzyme class?
A. Transferases
B. Ligases
C. Lyases
D. * Oxidoreductases
E. Isomerases
172. 
R-CH2OH + O2 > R-CHO + H2O2 which of the following types of enzymes 
catalyzes this reaction
A. Dehydrogenae
B. Oxidase
C. * Peroxidase
D. Aldolase
E. Catalase
173. 
Salivary amylase is an enzyme in humans that breaks down starch. The optimum 
pH for this reaction is 6.7. The rate of this reaction would not be affected by
A. * Maintaining the pH of the reaction at 6.7
B. Substrate concentration
C. Enzyme concentration
D. Decreasing the temperature of the reaction by 5oC
E. Maintaining the pH of the reaction at 7.7
174. 
Select the correct class of enzyme for this reaction. L-Glutamate + ATP + NH4+ -
--> L-glutamine + ADP + Pi
A. Oxidoreductase
B. Transferase
C. Hydrolase
D. Lyase
E. * Ligase
175. 
Select the correct class of enzyme for this reaction. L-aspartic acid + ґ-
ketoglutarate ---> oxaloacetic acid + L-Glutamate
A. Oxidoreductase
B. * Transferase
C. Hydrolase
D. Lyase
E. Ligase
176. 
Select the correct class of enzyme for this reaction. Sucrose + H2O ---> Fructose 
+ Glucose
A. Oxidoreductase
B. Transferase
C. * Hydrolase
D. Lyase
E. Ligase
177. 
Select the correct class of enzyme for this reaction. L-Glutamate + ATP + NH4+ -
--> L-Glutamine + ADP + Pi
A. Oxidoreductase
B. Transferase
C. Hydrolase
D. Lyase
E. * Ligase
178. 
Select the correct class of enzyme for this reaction. Polypeptide + H2O ---> 
Amino acids

---

A. Oxidoreductase
B. Transferase
C. * Hydrolase
D. Lyase
E. Ligase
179. 
The analysis demonstrated a 10 times increase of diastase activity. The danger of 
autolysis of a patient’s pancreas caused with activating of enzyme:
A. Amylase
B. Pepsin
C. * Trypsin
D. Lipase
E. Nuclease
180. 
The biooxidation of xenobiotics takes place due to microsomal oxidation with 
enzyme cytochrome P-450. What metal is the obligatory constituent of this enzyme?
A. * Fe
B. Zn
C. Na
D. Mg
E. K
181. 
The class of enzymes that split peptide bonds or glycosidic bonds with water is
A. * hydrolases
B. lyases
C. transferases
D. isomerases
E. oxidoreductases
182. 
The coenzyme biotin is involved in the transferring of the following groups
A. Amino group
B. * CO2
C. One carbon group
D. Acyl group
E. Amino acid residues
183. 
The coenzyme present in transaminase
A. NAD+
B. TPP
C. Coenzyme A
D. * Pyridoxal phosphate
E. Biotin
184. 
The defect of what enzyme results in disorders of decomposition of lactose at the 
inherited genetic disorders of synthesis of enzymes in a human organism:
A. Amylase
B. Maltase
C. Sucrase
D. * Lactase
E. Peptidase
185. 
The enzyme that catalyzes the reaction: glucose-6-phosphate + H2O > glucose + 
phosphate can be assigned to which enzyme class?
A. oxidoreductases
B. isomerases
C. lyases
D. * hydrolases
E. transferases
186. 
The enzyme which transfer groups between atoms within a molecule are

---

A. Recemases
B. Mutases
C. * Transferases
D. Oxido-reductases
E. All of these
187. 
The enzymes are inherent all physical and chemical properties of proteins, except:
A. High molecular mass
B. Breaking up to amino acid during a hydrolysis
C. Formation of colloid solutions
D. Antigen properties
E. * Stable to influence of high temperatures and salts of heavy metals
188. 
The function of peroxidases is:
A. To split off hydrogen atoms or electrons from substrates and transfer them to any 
acceptor except hydrogen peroxide and oxygen.
B. To split off hydrogen atoms or electrons from substrates and transfer them to 
oxygen.
C. * To split off hydrogen atoms or electrons from substrates and transfer them to 
hydrogen peroxide.
D. To decompose hydrogen peroxide.
E. To form hydrogen peroxide.
189. 
The important enzyme of saliva is alkaline phosphatase. What class of enzymes 
does it belong to?
A. * Hydrolases
B. Transferases
C. Oxidoreductases
D. Ligases
E. Lyases
190. 
The inactive precursor of an active enzyme is called
A. * Zymogen
B. Ribozyme
C. Isozyme
D. Abzyme
E. Nucleozyme
191. 
The inhibition of succinate dehydrogenase by malonate is an example for
A. * Competitive inhibition
B. Non competitive inhibition
C. Uncompetitive inhibition
D. Feedback or end product inhibition
E. None of these
192. 
The inhibitors of proteolytic enzymes were recommended for a patient. For what 
purpose necessary to apply such preparations:
A. * To avoid autolysis of pancreas.
B. To promote autolysis of pancreas.
C. To promote a hepatotoxity.
D. To reduce a hepatotoxity.
E. All answers are correct
193. 
The ions of what metal contain porphirine coenzymes?
A. Na
B. * Fe
C. Zn
D. Mo
E. Mn

---

194. 
The laboratory test allows diagnosing infarction of myocardium. The increase of 
what enzyme in blood proves it?
A. LDH4,5
B. Arginase
C. Pyruvate dehydrogenase
D. * AsAT
E. ALAT
195. 
The list of cofactors which are able in the process of fermentative reactions to 
carry electrons and protons is below resulted, except of one cofactor which carries 
chemical groups only. Choose it:
A. NAD
B. * Pyridoxal phosphate
C. FAD
D. Ubiqinon (coenzyme Q)
E. Hem coenzymes
196. 
The mechanism of action of lysozyme include
A. Distortion of the substrate
B. Acid catalysis
C. Proximity effects
D. Formation of a half-chair sugar form
E. * All of the above
197. 
The optimal pH for the enzyme pepsin is
A. * 1.0–2.0
B. 4.0–5.0
C. 5.2–?6.0
D. 5.8–6.2
198. 
The patient with cyanide poisoning was delivered to clinic. What mast be 
immediately used for the improvement of his state?
A. Glucose
B. Ascorbic acid
C. * Cytochromoxidase
D. Vitamin B1
E. Nicotine amide
199. 
The protective function of saliva is predefined a few mechanisms, including 
presence of enzyme, which has a bactericidal action, causes the lysis of polysaccharide 
complex of membranes of staphylococcuss, streptococci. Name this enzyme.
A. Beta-glyucuronidase
B. Alfa-amylase
C. Oligo-1,6-glucosidase
D. Collagenase
E. * Lysozyme
200. 
The term ligase refers to a class of enzymes that catalyzes_________.
A. Oxidation reduction reactions
B. Reactions involving the transfer of a functional group from one molecule to 
another
C. Hydrolytic cleavages
D. * Reactions where two molecules are joined together
E. All of the above
201. 
The uncompetitive inhibitor binds with
A. Active site
B. Allosteric site
C. * Enzyme substrate complex

---

D. Substrate
E. Product of reaction
202. 
TPP is a/an _____________ of yeast pyruvate decarboxylase.
A. Cosubstrate
B. Intrinsic factor
C. Metalloenzyme
D. Prosthetic group
E. * Coenzyme
203. 
Vitamins are essential to the survival of organisms because vitamins usually 
function as
A. Substrates
B. Nucleic acids
C. * Coenzymes
D. Nucleotides
E. Enzymes
204. 
What component is not included in the structure of holoenzymes?
A. Apoenzyme
B. Coenzyme
C. Cofactor
D. Prostetic group
E. * Izoenzyme
205. 
What enzymes are located in the ribosomes?
A. * Ligases.
B. Oxido-reductases.
C. Transferases.
D. Isomerases.
E. Hydrolases.
206. 
What enzymes catalyses the hydrolysis of triglycerides in the smal intestine?
A. * Lipases
B. Acetyl cholinesterases
C. Phospholipases
D. Transacylases
E. Monoglycerol lipases
207. 
What is the area of an enzyme called where the chemical reactions occur?
A. The Cytoplasm
B. * The Active Site
C. The Catalyst
D. The Nucleus
E. A substrate
208. 
What is the cause of primary enzymo-pathologies?
A. Liver diseases.
B. * Genetic disorders.
C. Trauma.
D. Ischemia.
E. All of these
209. 
What is the chemical nature of enzymes?
A. Carbohydrates.
B. Lipids.
C. * Proteins.
D. Nucleic acids.
E. Fatty acids
210. 
What kind of reaction do hydrolases catalyze?

---

A. * This group of enzymes catalyses hydrolytic cleavage reactions (such as the 
formation of glucose from maltose by the action of the enzyme maltase).
B. These enzymes are involved in electron transfer oxidation/reduction reactions, 
such as those in photosynthesis and cellular respiration.
C. These enzymes are involved in functional groups transfer
D. This group of enzymes catalyses none-hydrolytic cleavage reactions.
E. None of the above
211. 
What kind of reactions is catalized by hydrolases?
A. * Hydrolytic cleavage of substrates.
B. Oxidation-reduction reactions.
C. Addition to double bonds.
D. Formation of bonds with ATP cleavage.
E. Synthesis of compounds
212. 
What of the following statements are not true for the isoenzymes?
A. They differ in amino acid composition.
B. * They catalyze different reactions.
C. They differ in physical properties.
D. They are coded by different genes.
E. They active in different organs
213. 
What pathology is developed in the absence of phenylalanine 4-monooxygenase?
A. * Phenylketonuria.
B. Alkaptonuria
C. Galactosemia.
D. Hyperglycemia.
E. Achilia
214. 
What reactions would oxidoreductases is involved in?
A. This group of enzymes catalyses hydrolytic cleavage reactions (such as the 
formation of glucose from maltose by the action of the enzyme maltase).
B. * These enzymes are involved in electron transfer oxidation/reduction reactions, 
such as those in photosynthesis and cellular respiration.
C. These enzymes are involved in functional groups transfer
D. This group of enzymes catalyses none-hydrolytic cleavage reactions.
E. None of the above
215. 
What structure of proteins molecule is responsible for formation of active centre 
and for it catalytic action?
A. Primary
B. * Tertiary
C. Secondary
D. Quaternary
E. None from above
216. 
Where are the hydrolases located in the cell?
A. In mitochondria
B. In nucleus.
C. In cytoplasm
D. * In lysosoms
E. In complex Golgi
217. 
Which chemical is classified as an enzyme?
A. Galactose
B. Lipid
C. * Protease
D. Manganese dioxide
E. Sucrose

---

218. 
Which cofactor has the following properties: a) forms Schiff base, b) its precursor 
is absorb dietarily as Vitamin B6, c) is required in a number of reactions in aminoacid 
metabolism.
A. Thiamin pyrophosphate
B. Biotin
C. Lipoamide
D. * Pyridoxal phosphate
E. Nicotinamid
219. 
Which factor does not alter the rate of hydrolysis of maltose?
A. Temperature of the environment of the reaction
B. A pH of the environment of the reaction
C. Number of enzyme molecules present
D. * Size of the substrate molecule
E. None of the above
220. 
Which group of organic compounds includes the enzymes?
A. * Proteins
B. Starches
C. Carbohydrates
D. Lipids
E. Nucleic acids
221. 
Which of the following coenzymes functions in acyl transfer reactions?
A. NADPH
B. * Coenzyme A
C. Biotin
D. A and b
E. B and c
222. 
Which of the following enzymes would digest a fat?
A. Sucrase
B. Fatase
C. Protease
D. * Lipase
E. None of the above
223. 
Which property is common for enzymes and inorganic catalysts?
A. Specificity
B. Sensitiveness to the action of external factors
C. * Catalysis only thermodynamically possible reactions
D. Dependence from рН and temperature
E. High catalytic activity
224. 
Which statement describes the currently accepted theory of how an enzyme and 
its substrate fit together?
A. As the product is released, the enzyme breaks down.
B. The enzyme is like a key that fits into the substrate, which is like a lock.
C. The active site is permanently changed by its interaction with the substrate.
D. * As the substrate binds to the enzyme, the shape of the enzyme site changes to 
accommodate the reaction.
E. All of the above
225. 
Which statement is false about allosteric regulation?
A. * It is usually the mode of regulation for the last step in reaction pathways since 
this step produces the final product.
B. Cellular response is faster with allosteric control than by controlling enzyme 
concentration in the cell.

---

C. The regulation usually is important to the conservation of energy and materials in 
cells.
D. Allosteric modulators bind non-covalently at sites other than the active site and 
induce conformational changes in the enzyme.
E. B and C
226. 
Which statement is false about regulatory enzymes that are controlled 
allosterically?
A. * They are always less active when a modulator is bound to them.
B. They are often larger than other enzymes.
C. They have more than one binding site.
D. They often catalyze the first step in a reaction pathway.
E. They have more than two binding site.
227. 
Which statement regarding enzyme function is true?
A. Higher temperatures allow greater contact between enzymes and substrates; 
therefore, the higher the temperature the better the enzyme will function.
B. Enzymes cannot function at a pH lower than 6.
C. Most coenzymes are inorganic substances such as ions of iron or potassium.
D. Excessive salt ions can cause an enzyme to denature.
E. * All of the above.
228. 
Which type of specificity of enzymes does not exist?
A. Relative
B. Absolute
C. * Conformation
D. None of above
E. Stereospecificity
229. 
Which vitamins does not appear as coenzymes?
A. B1
B. B2
C. B5
D. * С
E. B12
230. 
Wich enzymes do not include porphyrine coenzymes?
A. Cytochrome b, с
B. Catalase
C. Peroxidase
D. * Phosphatase
E. Cytochrome а1, а
231. 
With ageing in cartilaginous decreases intensity of proteoglycans formation that 
leads to diminishing of degree of their hydratation and loss of tissues turgor. Activity of 
what enzymes of lysosomes does increase?
A. Deaminase, decarboxylase
B. Isomerase, dehydrogenases
C. Protease, lipase
D. Oxidoreductases, phosphstase
E. * Cathepsins, glycosidase
232. 
With urine of newborn was done a reaction with FeCI3 and a positive reaction 
(dark color) got. What disease is possible?
A. Galactosemia
B. Tirosinosis
C. * Phenylketonuria
D. Alkaptonuria
E. Aminoaciduria.

---

233. 
Zinc is present in which of the following enzymes
A. Cytochrome oxidase
B. Arginase
C. Hexokinase
D. * Alcoholdehydrogenase
E. Catalase
234. 
Zymogens are inactive enzyme precursors which are made active by
A. A change in structure
B. Selective proteolysis
C. Secretion to new types of cells
D. a and b
E. * a, b and c
235. 
An amphibolic pathway among the following is
A. HMP shunt
B. Glycolysis
C. * Citirc acid cycle
D. Gluconeogenesis
E. A and B
236. 
ATP is an energy-rich molecule because:
A. it contains adenine;
B. it contains monosaccharide ribose that can be oxidized with energy formation
C. * its triphosphate unit contains two phosphoanhydride bonds
D. it forms complex with Mg2+ or Mn2+
E. all of the above
237. 
Isocitrate dehydrogenase can use __________ as a cofactor.
A. NAD+ only
B. NADP+ only
C. * NAD+ or NADP+
D. FMN and FAD
E. TPP only
238. 
Isocitrate dehydrogenases is
A. * Aerobic dehydrogenase
B. Anaerobic dehydrogenase
C. Hydroperoxidase
D. Oxygenase
E. Ligase
239. 
Name the common product of the second stage of catabolism of carbonhydratess, 
lipids and amino acids.
A. * Acetyl-CoA.
B. Pyruvate
C. Citric acid.
D. Acyl-CoA.
E. ATP
240. 
Pyruvate dehydrogenase complex and ?-ketoglutarate dehydrogenase complex 
require the following for their oxidative decarboxylation:
A. COASH and Lipoic acid
B. NAD+ and FAD
C. COASH and TPP
D. * COASH, TPP,NAD+,FAD, Lipoate
E. A and C
241. 
Pyruvate dehydrogenase is a/an
A. Isomerase

---

B. Lyase
C. Ligase
D. * Oxido reductase
E. Transferase
242. 
The number of molecules of ATP produced by the total oxidation of acetyl CoA 
in TCA cycle is
A. 6
B. 8
C. 10
D. * 12
E. 15
243. 
Which of the following is located in the mitochondria?
A. Cytochrome oxidase
B. Succinate dehydrogenase
C. Dihydrolipoyl dehydrogenase
D. * All of these
E. None of these
244. 
Which of the following metabolite integrates glucose and fatty acid metabolism?
A. * Acetyl CoA
B. Pyruvate
C. Citrate
D. Lactate
E. None of the above
245. 
_____ is another term for biosynthesis.
A. Catabolism
B. * Anabolism
C. . Metabolism
D. Catalyst
E. Oxidation
246. 
A deficiency in thiamin causes the disease beriberi. Which might you expect to 
have a higher than normal blood concentration in an individual with this condition?
A. isocitrate
B. * pyruvate
C. oxaloacetate
D. acetyl CoA
E. malate
247. 
A patient was diagnosed with beri-beri disease. Activity of which enzyme is 
inhibited in an organism of the patient?
A. Fumarase
B. Citrate synthase
C. Malate dehydrogenase
D. Succinate dehydrogenase
E. * Pyruvate dehydrogenase
248. 
Among citric acid cycle enzymes, a flavoprotein is
A. Malate
B. Fumarase
C. * Succinate dehydrogenase
D. Isocitrate dehydrogenase
E. All of these
249. 
Among the many molecules of high-energy phosphate compounds formed as a 
result of the functioning of the citric acid cycle, one molecule is synthesized at the 
substrate level. In which of the following reactions does this occur?

---

A. Citrate C-ketoglutarate
B. * B-ketoglutarate --succinate
C. Succinate SSfumarate
D. Fumarate FFmalate
E. Malate MMoxaloacetate
250. 
Anabolic pathways _______
A. Do not depend on enzymes.
B. * Consume energy to build up polymers from monomers.
C. Lead to the synthesis of catabolic compounds.
D. Release energy as they degrade polymers to monomers.
E. All of the above
251. 
Anabolic reactions with the formation of new bonds and utilization of ATP energy 
are catalyzed by:
A. oxidoreductases;
B. hydrolases;
C. isomerases;
D. * ligases.
E. transferases
252. 
As resalt of hypovitaminosis a 55 years old man has sympthoms of oxidative 
decarboxilation of pyruvate inhibition. Oxidative decarboxilation of pyruvate results in 
formation of molecules ATP:
A. 2 ATP
B. * 3 ATP
C. 15 ATP
D. 12 ATP
E. 38 ATP
253. 
As resalt of hypovitaminosis a 55 years old woman has sympthoms of oxidative 
decarboxilation of pyruvate inhibition. Aerobic oxidation of pyruvate to CO2 and H2O 
results in formation of molecules ATP:
A. 38 ATP
B. 12 ATP
C. 3 ATP
D. * 15 ATP
E. 2 ATP
254. 
As resalt of hypovitaminosis and low activity of enzymes a man has sympthoms 
of oxidative decarboxilation of pyruvate inhibition. Cofactors of dehydrogenases are all, 
except one:
A. NAD+
B. * c-AMP
C. NADP+
D. FMN
E. FAD
255. 
Before pyruvic acid enters the TCA cycle it must be converted to
A. * Acetyl CoA
B. Lactate
C. Alfa-ketoglutarate
D. Citrate
E. Malate
256. 
Before pyruvic acid enters the TCA cycle it must be converted to
A. * Acetyl CoA
B. Lactate
C. Alfa-ketoglutarate

---

D. Citrate
E. Malate
257. 
Compounds like succinate, fumarate and а-ketoglutarate have a catalytic effect on 
the consumption of oxygen in a cell suspension. The rate of oxygen consumption is far 
more than that required for their own oxidation. This is evidence that ________.
A. they are intermediates in glycolysis
B. they act as enzymes to cause the oxidation of other compounds
C. * they are involved in a cyclic pathway
D. they must be cofactors for enzymes that are oxidoreductases
E. All of these
258. 
Dehydrogenation of succinic acid to fumaric acid requires the following hydrogen 
carrier:
A. NAD+
B. NADP+
C. * flavoprotein
D. Glutathione
E. FAD
259. 
Dehydrogenation of succinic acid to fumaric acid requires the following hydrogen 
carrier:
A. NAD+
B. NADP+
C. * Flavoprotein
D. Glutathione
E. Both A and C
260. 
During wet beriberi, peripheral vessels dilate and heart muscles loose their 
contractility. Some people think this is a result of a failure of the TCA cycle. Evidence 
for this is an increase in the
A. Rate of production of succinate
B. Rate of production of NADH
C. * Concentration of alpha-ketoglutarate and pyruvate
D. Production of ATP
E. Production of FADH2
261. 
During wet beriberi, peripheral vessels dilate and heart muscles loose their 
contractility. Some people think this is a result of a failure of the TCA cycle. Evidence 
for this is an increase in the
A. Rate of production of succinate
B. Rate of production of NADH
C. * Concentration of alpha-ketoglutarate and pyruvate
D. Production of ATP
E. Production of FADH2
262. 
For the two years old boy of a energy metabolism is inhibited due to processes of 
oxidation and ATP formation. Maintenance of metabolites of Krebs cycle in blood is 
decreased. What product of metabolism is the competitive inhibitor of Succinate 
dehydrogenase?
A. * Malonate
B. Malate
C. Aspartate
D. Glutamate
E. Citrate
263. 
For treatment of many diseases cocarboxylase (thiaminpyrophosphate) is used for 
providing of energy for cells. Choose what metabolic process is activated in this case?
A. * oxidative decarboxilation of pyruvate

---

B. deamination of glutamate
C. decarboxilation of histidin
D. transamination of aspartate
E. substrate level phosphorylation
264. 
How many ATP molecules can be derived from each molecule of acetyl CoA that 
enters the Krebs’ Cycle?
A. 6
B. * 12
C. 18
D. 38
E. 39
265. 
How many molecules of ATP are formed during the full oxidation of 1 molecule 
of acetyl CoA?
A. * 12.
B. 24.
C. 36.
D. 38.
E. 15.
266. 
How many molecules of NADH is formed during the conversion of ONE 
molecule of pyruvate to acetyl CoA?
A. * 1;
B. 2;
C. 3;
D. NADH2 is not formed, 1 molecule of NADPH is produced.
E. 4
267. 
How many substrate level phosphorylation reactions are in tricarboxylic acid 
cycle?
A. * 1;
B. 2;
C. 3;
D. 5;
E. there are not substrate level phosphorylation reactions.
268. 
Hyperproduction of insulin by pancreas of 35 years old patient caused activation 
of TCA. The citric acid cycle oxidizes pyruvate and some of the pathway intermediates 
are starting materials for many biosynthetic pathways. This means the citric acid cycle is 
a/an ______________.
A. amplifying pathway
B. strictly catabolic pathway
C. anaerobic pathway
D. * amphibolic pathway
E. both A and D
269. 
In blood and urine of a patient is increased value of pyruvic and ?-ketoglutaric 
acids. The deficiency of which coenzyme causes these changes?
A. Pyridoxal phosphate
B. * Thiamin pyrophosphate
C. Flavin mononucleotide
D. Biotin
E. Ubiqinon
270. 
In blood and urine of a patient it was takes place increase value of pyruvic and 
ketoglutaric acids. The deficiency of which coenzyme causes these changes?
A. Pyridoxal phosphate
B. * Thiamin pyrophosphate

---

C. Flavin mononucleotide
D. Biotin
E. Ubiqinon
271. 
In citric acid cycle, GDP is phosphorylated by
A. Succinate dehydrogenase
B. Aconitase
C. * Succinate thiokinase
D. Fumarse
E. Alfa-ketoglutarate dehydrogenase
272. 
Luck of insulin caused inhibition of TCA in the organism of 35 years old patient. 
For one turn of Krebs cycle ATP molecules are formed:
A. 38 ATP
B. * 12 ATP
C. 15 ATP
D. 1 ATP
E. 15 ATP
273. 
Metabolism is defined as:
A. a sequence of reactions that has a specific purpose;
B. * the entire network of chemical reactions carried out by living cells;
C. degradation of macromolecules molecules to create smaller molecules and 
energy;
D. synthesis of the molecules for cell maintenance, growth and reproduction.
E. none of the above
274. 
Most CO2 produced during aerobic cellular respiration is released during
A. Oxidative phosphorylation
B. Lactate fermentation.
C. * The Kreb’s cycle
D. Electron transport
E. Glycolysis.
275. 
NAD and NADP dependent dehydrogenases catalyze substrates by transferring 
__________ to C-4 of NAD+ and NADP+.
A. An electron
B. Two electrons
C. An electron and a proton
D. * Two electrons and a proton
E. Two electrons and two protons
276. 
NADH ____________ Krebs cycle and ATP _______________ it.
A. activates; activates;
B. activates; inhibits;
C. inhibits; activates;
D. * inhibits; inhibits;
E. none of the above.
277. 
One of the affects of thiamin deficiency in alcoholics is that muscles do not 
contract adequately. An explanation for this is that:
A. * Alpha-ketoglutarate in the TCA cycle requires thiamin
B. Glucose-6-phosphate dehydrogenase has an absolute requirement for thiamin
C. Pyruvate carboxylase has a requirement for thiamin
D. Thiamin is an intermediate in the electron transport chain
E. Myosin ATPase has an absolute requirement for thiamin
278. 
Organism suffers from hypovitaminosis of B5. How will it change the function of 
oxidoreductases?
A. It will inhibit synthesis and functions of cytochroms

---

B. It will inhibit synthesis and functions of FMN and FAD – dependent 
dehydrogenases
C. It causes improper synthesis and functions of TPP, which is the coenzyme of 
pyruvate dehydrogenase.
D. It causes inhibition of synthesis and functions of aminotransferases.
E. * It causes inhibition of synthesis and functions of NAD and NADP – dependent 
oxidoreductases (dehydrogenases)
279. 
Out of 24 mols of ATP formed in TCA cycle, 2 molecules of ATP can be formed 
at “substrate level” by which of the following reaction ?
A. Citric acid>?Isocitric acid
B. Isocitrate>?Oxaloacetate
C. Succinic acid>?Fumarate
D. * Succinyl CoA>?Succinic acid
E. A and B
280. 
Patient suffers from severe hypovitaminosis, low activity of dehydrogenases. 
Cofactors of dehydrogenases are all, except one:
A. NAD+
B. * c-AMP
C. NADP+
D. FMN
E. FAD
281. 
Patient with hypofunction of thyrod gland suffers from loose ob body weight as 
result of catabolism activation. Catabolism is characterized by _______________ of three 
major routs toward a final common pathway.
A. divergence;
B. * convergence;
C. splitting;
D. none of the above.
E. all of the above.
282. 
Patient with hypofunction of thyrod gland suffers from general weakness due to 
inhibition of metabolism. Metabolism is defined as:
A. a sequence of reactions that has a specific purpose;
B. * the entire network of chemical reactions carried out by living cells;
C. degradation of macromolecules molecules to create smaller molecules and 
energy;
D. synthesis of the molecules for cell maintenance, growth and reproduction.
E. none of the above
283. 
Pyruvate passes through the outer mitochondrial membrane by _____________.
A. * porin proteins
B. passive transport
C. pyruvate translocase
D. simple diffusion through the lipid bilayer
284. 
Pyruvate translocase is a/an _________________ protein that transports 
____________.
A. antiport; pyruvate and H+ in opposite directions
B. uniport; only pyruvate
C. * symport; pyruvate and H+ in the same direction
D. antiport; pyruvate and CO2 in opposite directions
E. symport; pyruvate and CO2 in the same direction
285. 
Rate of the TCA reactions in an organism of 55 years old patient with diabetes 
mellitus is decreased. The oxidation of acetyl CoA in citric acid cycle to CO2 and water 
is the _________ stage of catabolism and this is ___________ stage.

---

A. first, specific;
B. second, nonspecific;
C. third, specific;
D. * third, nonspecific.
E. second, specific.
286. 
Reduction of which one of the following substrates leads to a reducing equivalent 
in a step of the citric acid cycle?
A. Succinyl CoA
B. * Malate
C. Fumarate
D. Oxaloacetate
E. Citrate
287. 
Substrate level phosphorylation in TCA cycle is in step:
A. Isocitrate dehydrogenase
B. Malate dehydrogenase
C. Aconitase
D. * Succinate thiokinase
E. None of these
288. 
Substrate level phosphorylation in TCA cycle is in step:
A. Isocitrate dehydrogenase
B. Malate dehydrogenase
C. Aconitase
D. * Succinate thiokinase
E. Alfa-ketoglutarate dehydrogenase
289. 
The accumulation of pyruvate in blood, decrease of activity of transketolase of red 
blood cells takes place in organism of a 46 years old chronic alcoholic. Insufficiency of 
coenzyme form of which vitamin causes such changes?
A. * Thiamine diphosphate
B. Carboxybiotin
C. Metylcobalamin
D. Phosphopyridoxal
E. Tetrahydrofolate
290. 
The coenzyme electron carriers produced in the Krebs cycle are
A. ATP and ADP
B. Pyruvate and acetyl CoA
C. * FADH2 and NADH
D. NAD and NADH
E. NADH and ATP
291. 
The coenzyme not involved in the formation of acetyl-CoA from pyruvate is
A. TPP
B. * Biotin
C. NAD
D. FAD
E. Both A and B
292. 
The conversion of pyruvate to acetyl CoA and CO2
A. Is reversible
B. * Involves the participation of lipoic acid
C. Depends on the coenzyme biotin
D. Occurs in the cytosol
E. All of the above
293. 
The conversion of pyruvate to acetyl CoA and CO2
A. Is reversible

---

B. * Involves the participation of lipoic acid
C. Depends on the coenzyme biotin
D. Occurs in the cytosol
E. Both A and B
294. 
The high toxicness of ammonia for the neurons of CNS is predetermined braking 
of TCA and, as a result, decline of the tissue respiration, oxidative phosphorylation , 
ketonemia. Reason is a binding of ammonia to the following components of cycle:
A. * A - ketoglutarate
B. Isocitrate
C. Succinate
D. Fumarate
E. Oxaloacetate
295. 
The number of ATP produced in the succinate dehydrogenase step is
A. 1
B. * 2
C. 3
D. 4
E. 5
296. 
The number of ATP produced in the succinate dehydrogenase step is
A. 1
B. * 2
C. 3
D. 4
E. 5
297. 
?The patient with cyanide poisoning was delivered to clinic. What mast be 
immediately used for the improvement of his state?
A. Glucose
B. Ascorbic acid
C. * Cytochromoxidase
D. Vitamin B1
E. Nicotine amide
298. 
The rate at which pyruvate from glycolysis is used by the TCA cycle to produce 
energy is regulated by pyruvate dehydrogenase. During muscle contraction, this enzyme 
is
A. Inhibited by increases in the calcium concentration.
B. Activated by increased in acetyl CoA
C. Activated by increases in NADH
D. * Activated by increases in ADP
E. Inhibited by increases in AMP
299. 
Your patient is an alcoholic a buildup of a-ketoacids and symptoms of wet 
beriberi. All of the following might be part of a scenario that would explain why 
peripheral vessels dilate and cardiac muscles loose their contractility EXCEPT
A. Muscle needs ATP to contract
B. Most ATP is produced by oxidative phosphorylation
C. NADH and FADH2 are produced by the TCA cycle
D. The TCA cycle needs thiamine pyrophosphate to function
E. * A shortage of thiamine results in the inability to oxidize NADH
300. 
_____ is another term for biosynthesis.
A. Catabolism
B. Anabolism
C. * Metabolism
D. Catalyst

---

E. Oxidation
301. 
2,4-Dinitrophenol and oligomycin inhibit mitochondrial oxidative 
phosphorylation. 2,4-Dinitrophenol is an uncoupling agent; oligomycin blocks the ATP 
synthesis reaction itself. Therefore, 2,4-dinitrophenol will:
A. * Allow electron transfer in the presence of oligomycin.
B. Allow oxidative phosphorylation in the presence of oligomycin.
C. Block electron transfer in the presence of oligomycin.
D. Diminish O2 consumption in the presence of oligomycin
E. Do none of the above.
302. 
A chemical reaction that has a positive DeltaG is correctly described as _______
A. Exothermic.
B. Exergonic.
C. * Endergonic.
D. Enthalpic.
E. Spontaneous.
303. 
A chemical reaction with a positive Go' would be considered a/an
A. Exergonic reaction.
B. Energy generating reaction.
C. Catabolic reaction.
D. * Endergonic reaction
E. A and B
304. 
A compound with a greater free energy of hydrolysis than ATP is
A. Glucose 1-phosphate
B. Any phosphoester
C. * Phosphoenolpyruvate
D. Acetyl CoA
E. All of the above
305. 
A distinct set of metabolic reactions is called a reaction ________________.
A. Network
B. Cycle
C. * Pathway
D. Mechanism
E. A and B
306. 
A molecule who’s function is to release energy quickly is a
A. Fatty acids
B. Nucleic acids
C. * Monosaccharides
D. Amino acids
E. Vitamins
307. 
A process common to all living organisms, aerobic and anaerobic, is
A. * Glycolysis
B. Fermentation
C. The Krebs cycle
D. Electron transport chain reactions
E. Pyruvate oxidation
308. 
A reduced compound is
A. NAD
B. FAD
C. * NADH
D. ADP
E. ATP

---

309. 
A third class of inhibitors - hydrogen cyanide, hydrogen sulfide, and carbon 
monoxide block electron transport from:
A. Cytochrom c to CO2
B. * Cytochrome aa3 to oxygen
C. Cytochrom b to c
D. Cytochrom b to aa3
E. NADH to Fe-S proteins
310. 
After adding of 1-2 drops of NADI-reagent on the boiled portion of muscles the 
color doesn't appear - is the result of the:
A. Soulting-out of proteins
B. * Enzyme denaturation
C. Enzyme renaturation
D. Enzyme decarboxilation
E. Activation of enzymes
311. 
All of the following processes produce ATP, except:
A. * Lactic acid formation
B. Oxidative phosphorilation
C. Glycolysis
D. The Krebs cycle
E. The electron transport chain
312. 
All of the following statements about NAD+ are false except:
A. NAD+ has the appearance of a double nucleotide
B. * NAD+ is reduced to NADH by way of acceptance of a single electron and 
proton
C. NAD+ catalyzes the reactions of glycolysis by acting as an enzyme
D. NAD+ provides the energy necessary for the non-spontaneous reactions of 
glycolysis to occur
E. NAD+ has more chemical energy than does NADH
313. 
Almost all of the oxygen (O2) one consumes in breathing is converted to:
A. Acetyl-CoA.
B. Carbon dioxide (CO2)
C. Carbon monoxide and then to carbon dioxide.
D. None of the above.
E. * Water.
314. 
An electron transferred in a biological system is usually
A. Boosted to a higher light energy state
B. * Converted into other chemical compounds
C. Accompanied by a proton
D. Given off as radiant energy
E. Lost to the system as heat
315. 
As energy is being reconverted through the many forms, it is continuously lost as
A. Electricity
B. Light
C. Sound
D. Heat
E. * Chemical energy
316. 
At one time the uncoupler 2,4-dinitrophenol was used as a weight reducing drug. 
Its side-effects, including death, resulted in its discontinued use. How could this drug 
cause weight loss?
A. * The uncoupler allows the oxidation of fats from adipose tissue without the 
production of ATP. This allows the oxidation to proceed continuously and uses up 
the fats.

---

B. The uncoupler causes ATP to be produced at a much higher rate than normal and 
this causes weight loss.
C. The uncoupler inhibits the transport of pyruvate into the matrix of the 
mitochondria. Fats are then degraded to glycerol to subsequently to pyruvate to 
provide the necessary energy. Thereby depleting fat stores.
D. The uncoupler is an allosteric activator of ATP synthase. This increases the rate 
of translocation of H+ and the oxidation of fuels, including fats.
E. B and C only
317. 
ATP can be used to activate a substrate by
A. Phosphorylation
B. Adding a nucleotidyl group
C. Producing inorganic phosphate
D. * Both a and b
E. A, b, and c
318. 
ATP is the most commonly used source of energy rich compounds in cells 
because
A. It complexes with Mg++
B. It has a higher free energy of hydrolysis
C. Its products of hydrolysis are more stable the ATP
D. * It is used more often than other nucleoside triphoshates
E. It engages in phosphoryl-group transfers
319. 
ATP is thermodynamically suited as a carrier of phosphoryl groups in animal cells 
because
A. It is stable under cell conditions
B. It is not hydrolyzed in cells without enzyme action
C. It is intermediate in group-transfer potential
D. It can be produced from phosphocreatine
E. * All of the above
320. 
ATP synthase complexes can generate _______ATP(s) for each NADH that 
enters electron transport.
A. * 1
B. 2
C. 3
D. 4
E. 8
321. 
Carrier molecules in the cell membrane and metabolic energy are required for:
A. Osmosis
B. Facilitated diffusion
C. * Active transport
D. All the above
E. B & C only
322. 
Cells store energy when _____.
A. * The third phosphate group breaks off from an ATP molecule
B. They break down sucrose to glucose and fructose
C. A third phosphate group is bonded to an ATP molecule
D. Ions are released into the bloodstream
E. None of the above
323. 
Chemiosmotic generation of ATP is driven by
A. Phosphate transfer through the plasma membrane
B. Sodium, potassium pump
C. * A difference in H+ concentration on the two sides of the mitochondrial 
membrane

---

D. Osmosis of macromolecules
E. Large quantities of ADP
324. 
Consider the synthesis of a biopolymer in which the addition of successive 
monomers occurs by the same kind of reaction(s). The synthesis of the polymer is a 
________ pathway.
A. Linear
B. Cyclic
C. * Spiral
D. Branched
E. A and B
325. 
Cytochrome P450 is a two-enzyme sequence in eucaryotes, containing both FAD 
and FMN. The function of these coenzymes is
A. Reduce O2
B. React with foreign or natural substance indicated by RH
C. * Carry electrons from NADPH to oxygen
D. Provide a hydrophobic channel in the protein pocket
E. All of the above
326. 
During oxidative phosphorylation, the proton motive force that is generated by 
electron transport is used to:
A. Create a pore in the inner mitochondrial membrane
B. Generate the substrates (ADP and Pi) for the ATP synthase
C. * Induce a conformational change in the ATP synthase
D. Oxidize NADH to NAD+
E. Reduce O2 to H2O
327. 
Each NAD molecule carryng hydrogen to the electron transport chain can produce 
how mane moleculs of ATP?
A. 1
B. 2
C. * 3
D. 4
E. Cannot be determine
328. 
Energy from sunlight is trapped by chlorophyll located in the _____.
A. Citric acid cycle
B. * Mitochondria
C. Electron transport chain
D. Thylakoid membranes
E. Synthesis of urea
329. 
Energy is carried from catabolic to anabolic reactions in the form of
A. ADP
B. * High-energy ATP bonds
C. Coenzymes
D. Inorganic phosphate
E. Oxygen
330. 
Energy is released from ATP when the bond is broken between _____.
A. * Two phosphate groups
B. Adenine and ribose
C. Ribose and a phosphate group
D. Adenine and a phosphate group
E. B and C only
331. 
Energy requiring metabolic pathways that yield complex molecules from simpler 
precursors are:
A. Amphibolic

---

B. * Anabolic
C. Autotrophic
D. Catabolic
E. Heterotrophic
332. 
enough free energy to rephosphorylate:
A. 6 ATP
B. * 5 ATP
C. 4 ATP
D. 3 ATP
E. None of the above are correct
333. 
Enzymes are biological catalysts that enhance the rate of a reaction by:
A. * Decreasing the activation energy
B. Decreasing the amount of free energy released
C. Increasing the activation energy
D. Increasing the amount of free energy released
E. Increasing the energy of the transition state
334. 
Exergonic reactions
A. * Release potential energy
B. Consume energy
C. Form bonds
D. Occur only outside the cell
E. All of the above
335. 
Fermentation can be described as a process
A. * That takes place only in the absence of oxygen
B. In which the recipient of hydrogen atoms is an organic molecule
C. In which water is not one of the by-products
D. In which the Krebs cycle and electron transfer through ETS do not occur
E. All of the above are true
336. 
For normal mitochondria in the presence of an oxidizable substrate and an 
uncoupler such as 2,4-dinitrophenol which do you expect?
A. Oxygen consumption even in the absence of ADP
B. A rise in temperature to dissipate energy that would otherwise have been used to 
generate ATP
C. The flow of protons into the mitochondria matrix
D. * All of the above
E. None of the above
337. 
How many ATP molecules are produced when FADH2 delivers electrons to the 
electron transport system?
A. 1
B. * 2
C. 4
D. 36
E. 12
338. 
How many ATP molecules can be derived from each molecule of acetyl CoA that 
enters the Krebs’ Cycle?
A. 6
B. * 12
C. 18
D. 38
E. 39
339. 
How many reactions of substrate-level phosphorylation are in an organism?
A. 2.

---

B. * 3.
C. 4.
D. 5.
E. 12
340. 
If heat energy is absorbed by the system during a chemical reaction, the reaction is 
said to be:
A. At equilibrium
B. Endergonic
C. * Endothermic
D. Exergonic
E. Exothermic
341. 
If the free energy change ?G for a reaction is -46.11 kJ/mol, the reaction is:
A. At equilibrium
B. Endergonic
C. Endothermic
D. * Exergonic
E. Exothermic
342. 
In a fermentation metabolism, the organism produces ATP by
A. Generation of a proton motive force by transfer of electrons to oxygen
B. Substrate level phosphorylation
C. Oxidizing NADH to form the proton motive force
D. More than one of the above
E. * A, B, C
343. 
In a system where temperature is uniform, free energy is ___
A. * The energy available to do work.
B. The extra energy emitted by the system
C. The total energy of the system
D. Kinetic energy.
E. Equivalent to entropy.
344. 
In an electron carrier system, the net energy change is determined by the 
difference in reduction potentials between the
A. Primary electron donor and the terminal electron donor.
B. Primary electron acceptor and the terminal electron acceptor.
C. Primary electron acceptor and the terminal electron donor.
D. * Primary electron donor and the terminal electron acceptor.
E. Secondary electron acceptor and the terminal electron acceptor
345. 
In an exothermic chemical reaction
A. The mass of the products is greater than the mass of the reactants
B. The mass of the products is less than the mass of the reactants
C. * Heat is released as the reaction proceeds
D. Heat is absorbed as the reaction proceeds
E. None of the above
346. 
In cellular metabolism, ATP provides energy by:
A. Releasing heat upon hydrolysis
B. Acting as a catalyst in chemical reactions
C. Stealing electrons from glucose and it’s intermediates
D. * Releasing a terminal phosphate group
E. Oxidizing helper molecules
347. 
In normal mitochondria, the rate of NADH consumption (oxidation) will:
A. Be increased in active muscle, decreased in inactive muscle.
B. Be very low if the ATP synthase is inhibited, but increase when an uncoupler is 
added.

---

C. Decrease if mitochondrial ADP is depleted.
D. Decrease when cyanide is used to prevent electron transfer through the 
cytochrome a + a3 complex.
E. * All of the above are true.
348. 
In order for a reaction to proceed from left to right as written
A. ATP must be involved in the reaction
B. A common intermediate must be formed
C. * The overall free-energy changes must be negative
D. A phosphate group must be transferred
E. All of the above
349. 
In order to move molecules in your kidneys, your body needs _____.
A. * Energy
B. Sunlight
C. Cold
D. Heat
E. Only C and D
350. 
In oxidative respiration, energy is harvested from glucose molecules in a sequence 
of four major pathways. Which of the following is not one of these four pathways?
A. Krebs cycle
B. Glycolysis
C. Electron transfer through the transport chain
D. * Beta oxidation
E. Pyruvate oxidation
351. 
In respiration, the final electron acceptor in the electron transport chain is _____.
A. Oxygen
B. ATP
C. Hydrogen ions
D. * H2O
E. CO2
352. 
In the absence of oxygen, eukaryotic cells are restricted to
A. Chemiosmotic phosphorylation
B. Cyclic photo phosphorylation
C. Noncyclic photo phosphorylation
D. Oxidative phosphorylation
E. * Substrate level phosphorylation
353. 
In the complete process of photosynthesis, the _____.
A. Kory cycle yields CO2
B. * Light reactions release oxygen
C. Calvin cycle breaks down H2O
D. Light reactions produce NADP+ from NADPH + H+
E. All of the above
354. 
In the electron transport chain, the hydrogen ions enter the inner compartment of 
mitochondria through special channels formed by
A. * ATP synthase.
B. Coenzyme A
C. Acetyl CoA.
D. Oxygen.
E. Water
355. 
In the mitochondria NADH and QH2 are oxidized by ____________.
A. Carbon dioxide
B. Hydrogen peroxide
C. Ozone

---

D. * Oxygen
E. Water
356. 
In the presence of oxygen and in the absence of ADP, what occurs if the 
uncoupler 2,4-dinitrophenol is added to a suspension of normal mitochondria 5 minutes 
after an oxidizable substrate has been added?
A. The substrate will be oxidized until the addition of the 2,4-dinitrophenol which 
blocks further oxidation.
B. There is no effect; oxidation of the substrate continues at the same rate before and 
after the addition of 2,4-dinitrophenol.
C. The substrate cannot be oxidized either with or without 2,4-dinitrophenol unless 
ADP is also present.
D. * Oxidation of the substrate does not occur until the 2,4-dinitrophenol is added. 
Afterward, oxidation proceeds rapidly until all of the substrate is consumed.
E. The substrate will be reduced until the addition of the 2,4-dinitrophenol which 
blocks further reduction
357. 
In theory at least, the free energy provided by NADH is sufficient to form 
__________ ATP molecules.
A. 1
B. 2
C. 3
D. 4
E. * More than 4
358. 
Instant source of energy is ___________.
A. Amino acids
B. Sucrose
C. * Glucose
D. Fats
E. Vitamins
359. 
Intermediary metabolism is the term applied to reactions that _______________.
A. Degrade molecules
B. Synthesize large molecules such as proteins
C. Convert glucose to pyruvate
D. * Involve low molecular weight metabolites
E. Convert fats to fatty acid
360. 
Levels of ATP and ADP are maintained in cells by
A. Phosphotransferases
B. Nucleoside diphosphate kinase
C. Adenylate kinase
D. Oxidative phosphorylation
E. * All of the above
361. 
Most CO2 produced during aerobic cellular respiration is released during
A. Oxidative phosphorylation
B. Lactate fermentation.
C. * The Kreb’s cycle
D. Electron transport
E. Glycolysis.
362. 
Most CO2 produced during aerobic cellular respiration is released during
A. Oxidative phosphorylation
B. Lactate fermentation
C. * The Kreb’s cycle
D. Electron transport
E. Glycolysis

---

363. 
Most energy during cell respiration is harvested during
A. The Krebs cycle
B. * Oxidative phosphorilation
C. Glycolysis
D. Anaerobic respiration
E. Fermentation
364. 
Most oxidation reactions in microbial bioenergetics involve the
A. * Removal of electrons and hydrogens
B. Addition of electrons and hydrogens
C. Addition of oxygen
D. Removal of oxygen
E. None of the above
365. 
Organisms need a way of storing energy because _____.
A. A cell can't always immediately use all the energy it gets
B. An organism often has times when no energy is used
C. * A cell can release only stored energy
D. A cell cannot create energy and must get it from elsewhere in the organism
E. B and D
366. 
Oxidative phosphorylation is regulated by:
A. The availability of reduced cofactors from catabolic pathways.
B. The availability of the dNTPs.
C. * The availability of ADP and Pi.
D. A and C
E. A, B, and C
367. 
Oxidative phosphorylation requires all of the items listed below except
A. ATP synthase in the correct position in the membrane
B. Enzyme complexes embedded in a membrane
C. The flow of electrons from NADH and QH2 in the membrane
D. * A matrix more positively charged than the intermembrane space
E. A terminal electron acceptor which is O2 in mitochondria
368. 
Phosphorylation at the expense of ATP is catalyzed by __________.
A. Protein kinases
B. Phosphoryl isomerases
C. Phosphatases
D. * All of the above
E. None of the above
369. 
Regardless of the electron or hydrogen acceptor used, one of the products of 
fermentation is always:
A. ADP
B. ATP
C. NAD+
D. Pyruvate
E. * Alcohol
370. 
Respiration in addition to producing energy also carry out the function of
A. * Producing the major part of body heat
B. Manufacturing food
C. Maintaining water levels
D. None of the above
E. All the above
371. 
Several prosthetic groups act as redox centers in Complex I, including:
A. FMN, ubiquinone, iron-sulfur clusters, heme.
B. * FMN, ubiquinone, iron-sulfur clusters.

---

C. Heme, ubiquinone, iron-sulfur clusters.
D. All of the above
E. None of the above
372. 
Studying biogeochemical cycles would help a scientist learn how
A. Energy flows through an ecosystem
B. * Substances move in and out of living organisms
C. Chemicals react
D. Fatty acids are formed
E. A and B
373. 
Substrate-level phosphorylation differs from oxidative phosphorylation in that:
A. Substrate-level phosphorylation involves the transfer of electrons
B. Substrate-level phosphorylation only occurs in the cytosol
C. Oxidative phosphorylation only occurs in the cytosol
D. * Oxidative phosphorylation involves the transfer of electrons
E. GTP is always involved in substrate-level phosphorylation
374. 
The amount of energy recovered as ATP can be estimated by free energy of 
hydrolysis of
A. Phosphoester I bond in ATP
B. Phosphoanhydride bonds in ADP
C. Phosphoester bond I ADP
D. * Phosphoanhydride bonds in ATP
E. All of the above
375. 
The amount of energy required to bring all molecules to a reactive state prior to a 
chemical reaction is called the reaction's _____________.
A. Free energy of formation
B. * Activation energy
C. Van der Waal's energy
D. Go'
E. More than one of the above is correct
376. 
The chemical energy generated by oxidations cannot be captured by
A. NADH
B. NADP
C. FMN
D. FAD
E. * Q
377. 
The chemiosmotic theory explains
A. The phosphorylation of ADP
B. The electron transport chain
C. The differences between inner and outer mitochondrial membranes
D. * The source of energy for formation of mitochondrial ATP
E. Aerobic respiration
378. 
The coenzyme electron carriers produced in the Krebs cycle are
A. ATP and ADP
B. Pyruvate and acetyl CoA
C. * FADH2 and NADH
D. NAD and NADH
E. NADH and ATP
379. 
The coenzymes NAD and FAD carry electrons to the
A. Nucleus
B. Citric Acid cycle
C. Plasma membrane
D. * Electron transport system

---

E. Lysosoms
380. 
The degradation of which class of biochemicals does not significantly contribute 
to the release of energy to cells?
A. * Nucleic acids
B. Proteins
C. Lipids
D. Carbohydrates
E. B and C
381. 
The direct energy source that drives ATP synthesis during respiratory oxidative 
phosphorylation is
A. Oxidation of glucose to CO2 and water
B. The thermodynamically favorable flow of electrons from NADH to the 
mitochondrial electron transport carriers
C. Tthe final transfer of electrons to oxygen
D. * The difference in H+ concentration on opposite sides of the inner mitochondrial
E. membrane
F. Thermodynamically favorable transfer of phosphate molecules (from glycolysis 
and Krebs cycle intermediates) to ADP
382. 
The electron transport chain consists all of the following except
A. NADH dehydrogenase
B. Cytochrome complex
C. * Oxygenase
D. Cytochrome c oxidase
E. Ubiquinone, Q
383. 
The electrons released by FADH2 during its oxidation to FAD by the electron 
transport system finally end up as part of this molecule:
A. Glucose
B. * Water
C. Carbon dioxide
D. ATP
E. ADP
384. 
The electrons that enter the electron transport system are carried there by
A. NADH
B. FADH2
C. * Both A and B
D. Biotin
E. PALP
385. 
The energy for all forms of muscle contraction is provided by:
A. * ATP
B. ADP
C. Phosphocreatine
D. Oxidative phosphorylation
E. Generated in the mitochondria of the cell
386. 
The energy in glucose cannot be released by _____.
A. Glycolysis
B. * Burning
C. Respiration
D. Photosynthesis
E. None of the above
387. 
The energy produced during respiration is stored in
A. Pyruvic acid
B. Carbon dioxide

---

C. Adenosine monophosphate
D. * Adenosine triphosphate
E. Sialic acid
388. 
The energy that is necessary to break bonds in the reactant molecules and form 
new bonds in the products is called:
A. Delta E
B. * Activation energy
C. Transition state
D. Spontaneous energy
E. None of the above
389. 
The enzyme complexes associated with oxidative phosphorylation and the 
electron transport chain can be classified as ___________ proteins.
A. * Integral membrane
B. Peripheral membrane
C. Lipid-anchored membrane
D. Water-soluble
E. Both a and c
390. 
The enzymes of the Krebs cycle are located in the
A. Cytoplasm
B. Inter-membrane space of mitochondria
C. Vesicles of the ER
D. Outer membrane of the mitochondria
E. *Matrix of the mitochondria
391. 
The FADH2 formed during the TCA cycle enters the electron transport system at 
which site?
A. NADH dehydrogenase
B. Cytochrome a
C. Coenzyme Q
D. ATP synthase
E. Cytochrome c1
392. 
The final electron acceptor in the electron transport system is _____.
A. FADH2
B. * O2
C. Coenzyme Q
D. Cytochrome b
E. Cytochrome c
393. 
The first law of thermodynamics states that
A. Energy is the capacity to do work.
B. Doing work is defined as causing movement against a resisting force
C. Heat flows from a warmer body to a cooler body
D. * Energy is neither created nor destroyed
E. All of the above
394. 
The flow of material through a reaction pathway usually depends on 
________________.
A. * Control at several steps in the pathway
B. Control of the first step of the pathway
C. Covalent modification of the enzyme that catalyzes the reaction
D. Feed-forward activation
E. Control of the second step of the pathway
395. 
The formation of ATP from ADP and phosphate at the expense of the energy 
yielded by electron transport to oxygen is called:
A. * Oxidative phosphorylation

---

B. Substrate-level phosphorylation.
C. Tissue respiration
D. Peroxidation
E. Krebs cycle
396. 
The function of ATP is
A. * To provide energy for cellular processes
B. Catalyze chemical reactions
C. Make up long polymer chains
D. Store energy for a long time
E. Ingibit chemical reactions
397. 
The hydrolysis of the highest energy phosphate bond(s) in which of the following 
compounds will release the most free-energy?
A. Phosphoenolpyruurvate
B. ADP
C. AMP
D. ATP
E. * The energy generated by hydrolysis of the highest energy phosphate bond in all 
of the above is about the same.
398. 
The immediate energy source that drives ATP synthesis by ATP synthase during 
oxidative phosphorylation is:
A. The flow of electrons down the electron transport chain.
B. * The H+ concentration gradient across the inner mitochondrial membrane.
C. The oxidation of glucose and other organic compounds.
D. The transfer of phosphate to ADP.
E. The affinity of oxygen for electrons.
399. 
The inner mitochondrial membrane contributes to the formation of a proton 
gradient mainly because it
A. Contains ATP synthase complex
B. Is the location of specific transporter proteins
C. * Is a barrier to protons
D. Is not rich in proteins
E. Is rich in proteins
400. 
The loss of hydrogen is known as
A. Dehydration
B. Hydrogenation
C. Reduction
D. * Oxidation
E. Both D and D are correct
401. 
The most important flavin-linked dehydrogenases in the mainstream of respiration 
and electron transport, all localized in the:
A. ytosol
B. Nucleus
C. Rybosoms
D. * Mitochondria
E. Lysosoms
402. 
The movement of protons through ATP synthase occurs from the
A. Matrix to the intermembrane space.
B. Matrix to the cytoplasm.
C. * Intermembrane space to the matrix.
D. Intermembrane space to the cytoplasm.
E. Cytoplasm to the intermembrane space.

---

403. 
The notion that ATP is generated by a proton gradient existing across a membrane 
is called
A. Proton motion.
B. * Chemiosmotic theory
C. Cytochromic flow
D. Lactate reduction
E. A and D
404. 
The number of ATP molecules produced during aerobic and anaerobic respiration 
are _____ and ________ respectively.
A. 2 and 38
B. 0 and 2
C. 38 and 0
D. * 38 and 2
E. 1-10
405. 
The oxidation of a particular hydroxy substrate to a keto product by mitochondria 
has a P/O ratio of less than 2. The initial oxidation step is very likely directly coupled to 
the:
A. Oxidation of a flavoprotein
B. Oxidation of a pyridine nucleotide
C. * Reduction of a flavoprotein
D. Reduction of a pyridine nucleotide
E. Reduction of cytochrome a3
406. 
The oxidizing agent in the enzyme superoxide dismutase is
A. Superoxide anion (.O2-)
B. H2O2
C. * Copper
D. O2
E. All of the above
407. 
The oxygen utilized in cellular respiration finally shows up as
A. CO2
B. ATP
C. New O2
D. * H2O
E. Part of a sugar
408. 
The part of the respiratory tract that is responsible for keeping it healthy is 
________.
A. Trachea
B. Bronchi
C. Nasal cavity
D. * All the above
E. None of the above
409. 
The process by which a cell is built up from the simple nutrients obtained from its 
environment is called _____.
A. * Anabolism
B. Biosynthesis
C. Catabolism.
D. All of the above
E. More than one of the above, but not all
410. 
The process by which the sun’s energy is trapped as the source of energy used by 
virtually all living organisms?
A. Evolution
B. Metabolism

---

C. Adaptation
D. Homeostasis
E. * Photosynthesis
411. 
The process complementary to respiration is __________.
A. Circulation
B. * Photosynthesis
C. Osmoregulation
D. Hydroregulation
E. None of the above
412. 
The process shown is
A. Reduction and is endergonic
B. Reduction and is exergonic
C. Oxidation and is endergonic
D. Oxidation and is exergonic
E. A ang B
413. 
The protonmotive force is a result of _______________________.
A. The flow of electrons from the matrix to the inner membrane space
B. * A combination of an electrical potential and a chemical potential
C. The flow of protons within the inner mitochondrial membrane
D. All of the above
E. None of the above
414. 
The reaction, C6H6O6 + 6O2 = 6 CO2 + 6 H2O, when it occurs in living cells is 
known as
A. * Aerobic fermentation
B. Anaerobic fermentation
C. Cellular respiration
D. Glycolysis
E. Oxidative phosphorylation
415. 
The respiratory control center of humans is located in the
A. Blood-brain barrier
B. Alveoli
C. * Erythrocytes
D. Brainstem (medulla oblongata)
E. Trachea
416. 
The respiratory exchange ratio (RER) is the ratio of:
A. * Volume of oxygen consumed _ volume of carbon dioxide produced
B. Volume of carbon dioxide produced _ volume of oxygen consumed
C. Volume of oxygen produced _ volume of carbon dioxide consumed
D. Volume of oxygen consumed _ body mass
E. Volume of oxygen consumed _ lung ventilation
417. 
The role of oxygen in aerobic respiration is
A. To transport CO2
B. Most impotent in the Krebs cycle
C. To transport ekectrons in glycolysis
D. To provide electrons for the electron transport chain
E. * As the final hydrogen acceptor in the electron transport chain
418. 
The sequence describing the flow of electrons in phagocytes producing 
superoxide from oxygen is
A. O2 -> cytochrome b -> NADPH -> FADH
B. * NADPH -> FADH -> cytochrome b -> O2
C. NADH -> FADH -> cytochrome b -> O2
D. O2-> cytochrome b -> FADH -> NADPH

---

E. Cytochrome c -> cytochrome b -> NADPH -> FADH
419. 
?The standard free energy (?G°') of ATP hydrolysis to ADP + Pi is about
A. +30 kJ/mol
B. +14 kJ/mol.
C. -14 kJ/mol.
D. * -30 kJ/mol.
E. -62 kJ/mol.
420. 
The synthesis of one molecule of ATP from ADP requires _________ to be 
translocated across the inner mitochondrial membrane.
A. One proton
B. * About two protons
C. Hundreds of protons
D. 1 mole of protons
E. 10 protons
421. 
The term coupling in biochemistry can mean
A. Phosphorylating ADP along with the transport of electrons in mitochondria
B. Forming oxygen from superoxide anion
C. Linking reactions so that one cannot occur without the other
D. All of the above
E. * a and c
422. 
The transfer of free energy from catabolic pathways to anabolic pathways is best 
called
A. Feedback regulation
B. Bioenergetics
C. Cooperativity
D. * Energy coupling
E. Entropy
423. 
The types of ‘work ‘ cells do include
A. Chemical workmaking and breaking bonds
B. Transport of nutrients into cells and waste products out
C. Movement of individual cells and stuff within a cell
D. Cells do not do work, only tissues do work
E. * A and c are correct
424. 
Uncoupling of mitochondrial oxidative phosphorylation:
A. Allows continued mitochondrial ATP formation, but halts O2 consumption.
B. Halts all mitochondrial metabolism.
C. * Halts mitochondrial ATP formation, but allows continued O2 consumption.
D. Slows down the citric acid cycle.
E. Slows the conversion of glucose to pyruvate by glycolysis.
425. 
What needs the nutrients and oxygen carried by your blood?
A. rgan systems
B. rgans
C. * issues
D. ndividual cells
E. Spesific cells
426. 
What system transports oxygen and nutrients to the cells of your body?
A. The digestive system
B.
C. *
D.
E. A and D
427. 
What tissue we used for the detection of cytochrome oxidase?

---

A. Blood
B. * Spleen
C. Muscle
D. Liver
E. Heart
428. 
What type of protein such as a channel protein cross the entire cell membrane?
A. Integral protein
B. Peripheral protein
C. * Transmembrane protein
D. Receptor protein
E. A and B
429. 
What type of transport utilizes ATP?
A. * Active transport
B. Diffusion
C. Facilitated diffusion
D. Osmosis
E. Only B and C
430. 
When 10,000 molecules of ATP are hydrolyzed to ADP and in a test tube, about 
twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP. 
Which of the following is the best explanation for this observation?
A. Cells are less efficient at heat production than nonliving systems.
B. Cells convert some of the energy of ATP hydrolysis into other forms of energy 
besides heat.
C. * Cells are open systems, but a test tube is a closed system.
D. The hydrolysis of ATP in a cell produces different chemical products than does 
the reaction in a test tube.
E. The reaction in cells must be catalyzed by enzymes, but the reaction in a test tube 
does not need enzymes.
431. 
When a phosphate is transferred from a high-energy molecule of ADP to form 
ATP it's referred to as _____.
A. Photophosphorylation
B. Substrate-level phosphorylation
C. * Oxidative phosphorylation
D. Citric cycle
E. Decarboxilation of pyruvat
432. 
When O2 is reduced during the electron transport system, _____ is produced.
A. * H2O
B. CO2
C. ADP
D. Glucose
E. Pyruvat
433. 
When the ?G'° of the ATP synthesis reaction is measured on the surface of the 
ATP synthase enzyme, it is found to be close to zero. This is thought to be due to:
A. A very low energy of activation
B. Enzyme-induced oxygen exchange
C. Stabilization of ADP relative to ATP by enzyme binding
D. * Stabilization of ATP relative to ADP by enzyme binding
E. None of the above
434. 
When xenobiotics are substrates for the protein called cytochrome P450, this 
enzyme serves to
A. Provide oxidation
B. Solubilize natural metabolites

---

C. Solubilize steroids
D. * Solubilized drugs, anaesthetic, dyes and pesticides
E. All of the above
435. 
Which has the highest reduction potential?
A. NADH
B. Complex I
C. Complex II
D. * O2
E. Cytochrom c
436. 
Which is not generally a molecule used to conserve energy?
A. ATP
B. NADH
C. FAD
D. * QH2
E. All of the above
437. 
Which is true for aerobic respiration but not true for anaerobic respiration?
A. CO2 is produced
B. ATP is produced
C. * Water is produced
D. Alcohol is produced
E. Pyruvate is produced
438. 
Which is usually the slowest way to regulate a reaction in a metabolic pathway?
A. Allosteric modulation
B. Covalent modification
C. * Changing the enzyme concentration
D. All of the above are usually equally as fast
E. Competitive inhibitor
439. 
Which metabolic pathway is common to both fermentation and cellular 
respiration?
A. The Kreb’s cycle
B. Reduction of pyruvate to lactate
C. * Glycolysis
D. Synthesis of acetyl CoA from pyruvate
E. The electron transport chain
440. 
Which molecule is an electron carrier that is carrying electrons?
A. NaCl
B. NAD+
C. * NADH
D. NH4
E. (NH4)2SO4
441. 
Which of the following coenzymes would have to be continually present in the 
cell in order for the oxidative reactions of glycolysis to continue?
A. FADH2
B. NADH
C. ATP
D. * NAD+
E. All of the above
442. 
Which of the following is a coenzyme associated with cellular respiration?
A. NAD+
B. O2
C. FAD
D. * both A and C

---

E. PALP
443. 
Which of the following is common to both cellular respiration and the light 
reactions of photosynthesis?
A. The transfer of electrons to glucose
B. The chemiosmotic formation of ATP
C. * Oxygen is one of the byproducts
D. Mitochondria are essential organelles E. must have light
E. A and B
444. 
Which of the following is correct concerning the mitochondrial ATP synthase?
A. It can synthesize ATP after it is extracted from broken mitochondria.
B. It catalyzes the formation of ATP even though the reaction has a large positive 
?G'°.
C. It consists of F0 and F1 subunits, which are transmembrane (integral) 
polypeptides.
D. It is actually an ATPase and only catalyzes the hydrolysis of ATP.
E. * When it catalyzes the ATP synthesis reaction, the ?G'° is actually close to zero.
445. 
Which of the following is most similar in structure to ATP?
A. DNA helix
B. Phospholipid
C. RNA nucleotides
D. An anabolic steroid
E. * An amino acid with three phosphate groups attached
446. 
Which of the following is not a factor contributing to the large free energy of 
hydrolysis of ATP?
A. Electrostatic repulsion of oxygen atoms
B. Better solvation of products than ATP itself
C. * Complexes with Mg++ or Mn++ ions
D. Better stability of products than ATP itself
E. Electrical sheilding of products of hydrolysis
447. 
Which of the following is not a part of adenosine diphosphate?
A. * Glucose
B. Adenine
C. Ribose
D. Two phosphate groups
E. All of the above
448. 
Which of the following is true for all exergonic reactions?
A. A net input of energy from the surroundings is required for the reactions to 
proceed.
B. The products have more total energy than the reactants.
C. The reactions are nonspontaneous.
D. * The reaction proceeds with a net release of free energy.
E. The reactants have more total energy than the products
449. 
Which of the following is true for all exergonic reactions?
A. The products have more total energy than the reactants.
B. * The reaction proceeds with a net release of free energy.
C. A net input of energy from the surroundings is required for the reactions to 
proceed.
D. Some reactants will be converted to products.
E. The reactions are nonspontaneous.
450. 
Which of the following is true for exergonic reactions?
A. The reactions upgrade the free energy in the products at the expense of energy 
from the surroundings.

---

B. A net input of energy from the surroundings is required for the reactions to 
proceed.
C. * The products have less free energy than the reactants.
D. The products have more free energy than the reactants.
E. Reactants will always be completely converted to products.
451. 
Which of the following produced a product used for synthesis of subsrate-level 
phosphorylation?
A. Phosphophructikinase
B. Aldolase
C. * Glyceraldehyd-3-phosphate dehydrogenase
D. 1,3 – bisphophoglycerate mutase
E. All of the above
452. 
Which of the following reactions contains steps which require an input of ATP 
before they can be completed?
A. * Glycolysis
B. Kreb’s cycle
C. Electron transport system
D. A and b
E. B and c
453. 
Which of the following statements about energy conservation in the 
mitochondrion is false?
A. Drug that inhibits the ATP synthase will also inhibit the flow of electrons down 
the chain of carriers.
B. For oxidative phosphorylation to occur, it is essential to have a closed 
membranous structure with an inside and an outside.
C. The yield of ATP per mole of oxidizable substrate depends on the substrate.
D. * Uncouplers (such as dinitrophenol) have exactly the same effect on electron 
transfer as inhibitors such as cyanide; both block further electron transfer to 
oxygen.
E. Uncouplers “short circuit” the proton gradient, thereby dissipating the proton 
motive force as heat.
454. 
Which of the following statements about the chemiosmotic theory is false?
A. Electron transfer in mitochondria is accompanied by an asymmetric release of 
protons on one side of the inner mitochondrial membrane.
B. Energy is conserved as a transmembrane pH gradient.
C. Oxidative phosphorylation cannot occur in membrane-free preparations.
D. The effect of uncoupling reagents is a consequence of their ability to carry 
protons through membranes.
E. * The membrane ATPase, which plays an important role in other hypotheses for 
energy coupling, has no significant role in the chemiosmotic theory.
455. 
Which of the following statements about the mitochondrial inner membrane is 
(are) not true?
A. The inner membrane is permeable to CO2, H2O, and small ions.
B. The inner membrane contains about 75% protein.
C. * The inner membrane contains many respiratory proteins.
D. The inner membrane is highly invaginated.
E. All of the above are true
456. 
Which of the following statements about the mitochondrial inner membrane is 
(are) not true?
A. The inner membrane is permeable to CO2, H2O, and small ions.
B. The inner membrane contains about 75% protein.
C. The inner membrane contains many respiratory proteins.

---

D. The inner membrane is highly invaginated.
E. * All of the above are true
457. 
Which of the following statements are true about oxidative phosphorylation?
A. Electron transport provides energy to pump protons into the intermembrane space.
B. * An electrochemical gradient is formed across the inner mitochondrial 
membrane.
C. Potassium and sodium ions form an ionic gradient across the inner mitochondrial 
membrane.
D. A and B
E. A, B, and C
458. 
Which of the following statements are true about oxidative phosphorylation?
A. Electron transport provides energy to pump protons into the intermembrane space.
B. An electrochemical gradient is formed across the inner mitochondrial membrane.
C. Potassium and sodium ions form an ionic gradient across the inner mitochondrial 
membrane.
D. * A and B
E. A, B, and C
459. 
Which of the following statements is false?
A. Phosphofructokinase is the rate limiting enzyme in glycolysis
B. Phosphorylase activity is higher in Type II fibres than in Type I fibres
C. Endurance training increases the amount of TCA cycle enzymes in muscle
D. * Oxygen is consumed in the TCA cycle
E. The heart can oxidise lactate
460. 
Which of the following statements is TRUE concerning catabolic pathways?
A. They build up complex molecules such as protein from simpler compounds.
B. They combine molecules into more complex and energy-rich molecules.
C. They are spontaneous and do not need enzyme catalysis.
D. They involve endergonic reactions that break complex molecules into simpler 
ones.
E. * They are usually coupled with anabolic pathways to which they supply energy 
in the form of ATP.
461. 
Which of the following takes place during oxidative phosphorilation in 
mitochondria
A. Protons are pumped from the matrix to the intermembrane space
B. Protons are pumped from the intermembrane space to the matrix
C. Electrons are pumped from the matrix to the intermembrane space
D. * Electrons are pumped from the intermembrane space to the matrix
E. NADP is pumped from the matrix to the intermembrane space
462. 
Which of the following would be considered one of a cell's electron carriers?
A. ATP
B. * NADH
C. FAD
D. All of the above
E. More than one of the above, but not
463. 
Which statement does not explain why many biochemical processes are carried 
out via multi-step pathways rather than by single-step reactions (or only a few steps)?
A. Multi-step pathways allow for more control points to regulate biochemical 
processes.
B. * The end products of most pathways can usually be produced only by the 
pathway reactions that nature has evolved.
C. Sharing of intermediates between pathways is facilitated this way.

---

D. There is greater control over the amounts of energy that are consumed or released 
at any one time.
E. None of the above
464. 
Which statement is false about most metabolic pathways?
A. * Most pathways are reversible under physiological conditions.
B. Pathways serve to increase the efficiency of energy transfers.
C. The rates of pathway reactions vary to respond to changing conditions.
D. The enzymes that catalyze reactions in metabolic pathways generally catalyze 
only a single step.
E. Most pathways are irreversible under physiological conditions.
465. 
Which statement is not true about catabolic pathways?
A. They have a net release of energy.
B. They have a net consumption of ATP.
C. They liberate smaller molecules from larger ones.
D. They include the citric acid cycle.
E. A and C only
466. 
Which statement is true about two reactions that are coupled?
A. * One reaction will normally not occur without the other.
B. One is always exergonic and the other is always endergonic.
C. Only oxidation-reduction reactions can be coupled.
D. Coupled reactions are always driven by the ATP to ADP conversion.
E. B and C
467. 
Which sugar is a part of adenosine diphosphate?
A. Adenine
B. * Ribose
C. Glucose
D. Glycogen
E. Water
468. 
Which term most precisely describes the general process of breaking down large 
molecules into smaller ones?
A. Anabolism
B. Catalysis
C. * Catabolism
D. Dehydration
E. Metabolism
469. 
Why is ATP an important molecule in metabolism?
A. It energizes other molecules by transferring phosphate groups
B. Its phosphate bonds are easily broken
C. Hydrolysis of its phosphate groups is endergonic
D. Hydrolysis of its phosphate groups is exergonic
E. * A, b, and d are correct
470. 
Why is ATP an important molecule in metabolism?
A. It energizes other molecules by transferring phosphate groups
B. Its phosphate bonds are easily broken
C. Hydrolysis of its phosphate groups is endergonic
D. Hydrolysis of its phosphate groups is exergonic
E. * A, b, and c are correct
471. 
Within the inner matrix of the mitochondrion are:
A. * The enzymes of the tricarboxylic acid cycle (Krebs’ cycle)
B. The components of the electron transport chain
C. Glycogen molecules
D. The enzymes of gluconeogenesis

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E. The enzymes creatine kinase and carnitine acyl transferase 1