Lipids And Membrane Structure

Question 1

Lipid function

Answer 1

1. Energy store
2. Precursor for vitamin/hormone
3. Bile acids
4. Membrane structure

Question 2

4 head groups in phosphate heads

Answer 2

1. Inositol
2. Choline
3. Ethanolamine
4. Serine

Question 3

General structure of phospholipid

Answer 3

Aa
Phosphate
Glycerol
2FA

Question 4

Phosphatidylcholine structure

Answer 4

Choline
Phosphate
Glycerol
2FA

Question 5

Sphingomyelin structure

Answer 5

Choline
Phosphate
Ceramide (sphingosine+FA)

Question 6

Which phospholipids face inside, which face outside?

Answer 6

In: phosphatidylethanolamine/phosphatidylserine

Out: sphingomyelin/phosphatidylcholine

Question 7

What determines membrane fluidity

Answer 7

Short FA: increases fluidity

Unsaturated FA: kinks increase fluidity

Cholesterol: decreased fluidity

Question 8

3 types of membrane proteins

Answer 8

1. Integral: alpha/beta
2. Anchored: covalently bonded to FA/ glycolipid
3. Peripheral: ionically to integral proteins/phospholipid

Question 9

Anchored membrane protein examples

Answer 9

Glycolipid: alkaline phosphatase

FA: RAS

Question 10

Peripheral membrane protein example

Answer 10

Spectrin

Question 11

Phspholipase types and sites of action

Answer 11

1. PLA1: FA furthest from head
2. PLA2: FA closest to head
3. PLB: PLA1&2
4. PLC: head
5. PLD: aa

Question 12

Effect of high salt/urea on peripheral/anchored/integral proteins

Answer 12

All remain but peripheral

Question 13

Effect of phospholipases on peripheral/anchored/integral proteins

Answer 13

Peripheral: removed/remain
Anchored: removed
Integral: remain

Question 14

Effect of detergent on peripheral/anchored/integral proteins + mechanism

Answer 14

All removed

Detergent monomers -> micelles -> water-soluble protein-lipid-detergent complex + water-soluble lipid-detergent micelles

Question 15

saturated unsaturated polyunsaturated FA example

Answer 15

stearic (18:0)
oleic (18:1)
arachnidonic (20:4)