The Cell Membrane Homeostasis & Cellular Transport

Osmosis Concentration

• Hypertonic: the water or solution OUTSIDE of the cell is saltier than the INSIDE of the cell.
• Hyper = “more” ore “above”
• This will cause it to shrivel, and shrink
• Ex. Pouring salt on a slug will cause it to shrink

Osmosis Concentration

• Hypotonic: the water or solution OUTSIDE of the cell
• Hypo means “less than” or “below”
• A hypotonic solution will cause the cell to take in water, and swell

Osmosis Concentration

• Isotonic: the water outside of the cell has an EQUAL amount of salt as the water INSIDE of the cell.
• Iso means “equal”
• Will cause NO CHANGE in cell size

Interactive Red Blood Cell
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Types of Active Transport

• Active transport uses ENERGY (ATP)
• EXOcytosis = how materials EXIT the cell (how the cell uses the bathroom)
• ENDOcytosis = how materials ENTER the cell (cell eating/engulfing)
• PINOcytosis= how small materials ENTER the cell (cell eating/engulfing)
• PHAGOcytosis = how larger materials ENTER the cell (cell eating/engulfing)

Active Transport
Active transport is the movement of molecules from LOW to HIGH concentration.
Energy is required as molecules must be pumped against the concentration gradient.
Proteins that work as pumps are called protein pumps.
Ex: Body cells must pump carbon dioxide out into the surrounding blood vessels to be carried to the lungs for exhale. Blood vessels are high in carbon dioxide compared to the cells, so energy is required to move the carbon dioxide across the cell membrane from LOW to HIGH concentration.
outside of cell
inside of cell
Carbon Dioxide molecules
NO ENERGY NEEDED:
Diffusion
Osmosis
Facilitated Diffusion
ENERGY NEEDED:
Active Transport
ANALOGY: Passive Transport vs. Active Transport
Passive Transport: Like going DOWNHILL
Active Transport: like going UPHILL