Membranes

Question 1

The structure of membranes depends on ___

Answer 1

• Fluidity

- Functional proteins

Question 2

What are membranes mainly composed of?

Answer 2

Proteins

Question 3

Accepted model of membranes

Answer 3

Fluid Mosaic

Question 4

Several lipids within membranes

Answer 4

1. Phospholipids
2. Glycolipids
3. Sterols

Question 5

Rotation and lateral diffusion

Answer 5

Rapid and random

Question 6

Transverse diffusion

Answer 6

Rare and regulated

Question 7

Transition temperature (Tm)

Answer 7

The temperature of which a lipid bilayer becomes fluid

Question 8

Effects of chain length on Tm

Answer 8

Longer fatty acid chains decrease membrane fluidity

Question 9

Effects of unsaturation on Tm

Answer 9

Double bonds in unsaturated fatty acids increase fluidity

Question 10

Fluidity Buffer

Answer 10

Maintains membrane fluidity in response to changes in temperature

Question 11

Homeoviscous Adaptation

Answer 11

Change in length and degree of saturation of fatty acids to compensate for temperature changes

Question 12

Lipid Rafts

Answer 12

Localized micro-domains of membrane lipids with specific proteins
- Low fluidity

Question 13

3 categories of membrane proteins

Answer 13

1. Integral membrane proteins
2. Peripheral proteins
3. Lipid-anchored proteins

Question 14

Integral membrane proteins

Answer 14

Embedded in lipid bilayer

- Have hydrophobic domains

Question 15

Peripheral proteins

Answer 15

Located on one side of the bilayer

Question 16

Lipid-anchored proteints

Answer 16

Covalently attached to lipid molecules embedded in the bilayer

Question 17

Glycosylation

Answer 17

Linkage of a carbohydrate to a protein

Question 18

Glycoproteins

Answer 18

Prominent in plasma membranes

- Important for cell-cell recognition and signaling