Membrane Structure and Function

Question 1

The cell membrane is composed of ____% _____ and ____% ______. The basic makeup molecule is a ___________, with two fatty acid tails, a glycerol and a _________ group.

Answer 1

50, protein, 50, lipid, phospholipid, phosphatidyl

Question 2

What effect does cholesterol have on the lipid membrane?

Answer 2

1. Increases the rigidity of the membrane (sterol group)

2. Decreases the permeability of the bilayer to water soluble molecules.

Question 3

Phospholipids ________ when in water, with ______ regions in the center and ______ regions on the outside.

Answer 3

aggregate hydrophobic, hydrophilic (hence the lipid bilayer formation)

Question 4

Hydrophobic interactions allow for tremendous what?

Answer 4

plasticity and membrane fluidity

Question 5

What does fluidity (relative mobility of lipids in a membrane) depends on?

Answer 5

Lipid composition and temperature.

Question 6

Which structures are formed from bilipid layers?

Answer 6

golgi, nuclear membrane, mitochondria

Question 7

What is the transition temperature?

Answer 7

When a lipid freezes

Question 8

Sphinolipids and cholesterol rich regions occurs with which structure?

Answer 8

lipid rafts