3. The Plasma Membrane

Question 1

What are the three most common lipids in the plasma membrane?

Answer 1

phospholipids
glycolipids
cholesterol

Question 2

Why do phospholipids spontaneously arrange themselves into a lipid bilayer?

Answer 2

steric hindrance

Question 3

What are cell-surface receptors?

Answer 3

proteins that bind extracellular signaling molcules and relay the signal to the cell

Question 4

What are channel proteins?

Answer 4

proteins that selectively allow ions or molecules to cross the membrane

Question 5

What are integral membrane proteins?

Answer 5

proteins embedded in the membrane and held there by hydrophobic interactions

Question 6

What are peripheral membrane proteins?

Answer 6

proteins that are not embedded in the membrane, rather held to integral membrane proteins by hydrogen bonding and electrostatic interactions

Question 7

What is the fluid mosaic model?

Answer 7

current understanding of membrane dynamics

Question 8

How can lipids move in the fluid mosaic model?

Answer 8

laterally, cannot flip or reverse due to hydrophobic interactions

Question 9

What affects membrane fluidity?

Answer 9

amount of cholesterol and saturation/tail length of fatty acids