Cell Membranes

Question 1

Intrinsic Proteins

Answer 1

Proteins that go straight through the protein channel.

Question 2

Extrinsic Proteins

Answer 2

Proteins that are on the surface or embedded in the membrane as they are too big to fit through the protein channel

Question 3

Cholesterol (produced in the liver)

Answer 3

• Adds STRENGTH to membranes and is dotted throughout the membrane.
• VERY hydrophobic
• reduces lateral movement of other molecules including phospholipids.
• makes the membrane less fluid at high temps.
• Prevents leakage of water and dissolved ions from the cell.
• Cholesterol pulls together fatty acid tails of the phospholipid molecules.