Glycolysis — Splitting Glucose to Form Pyruvic Acid By far the most important means of
releasing energy from the glucose molecule is initiated by glycolysis. The endproducts of glycolysis
are the oxidized to provide energy. Glycolysis means splitting of the glucose molecule to form two moleculesof pyruvic acid. Glycolysis occurs by 10 successive chemical reactions, shown in Figure 67-
5. Each step is catalyzed by at least one specific protein enzyme. Note that glucose is first converted
into fructose-1,6-diphosphate and then split into two three-carbonatom molecules, glyceraldehyde-3-
phosphate, each of which is then converted through five additional steps into pyruvic acid.
Formation
of ATP During Glycolysis.
Despite the many chemical reactions in the glycolytic series, only a small
