Block 1 Lecture 2

Question 1

how are peripheral proteins bonded

Answer 1

noncovalently with integral proteins

Question 2

what does amphipathic mean

Answer 2

having both hydrophobic and hydrophilic parts

Question 3

what is the phospholipid bilayer composed of

Answer 3

1. glycerol backbone
2. 2 fatty acyl tails in ester linkage
3. a polar head group

Question 4

are sphingolipids amphipathic

Answer 4

yes

Question 5

what are sphingolipids composed of

Answer 5

1. sphingosine backbone
2. 1 fatty acid tails in amide
3. a polar head group
4. either a carbohydrate or a phosphate ester of another alcohol

Question 6

what do cholesterols do in the lipid bilayer

Answer 6

wedge into bilayer and has effect on fluidity by interacting with first few hydrocarbon groups on phospholipid tails

Question 7

what are some characteristics of cholesterols

Answer 7

amphipathic and sterol

Question 8

what do unsaturated fatty acids contain

Answer 8

one or more double bonds

Question 9

what does membrane fluidity depend on

Answer 9

• lipid composition
• fatty acid chain length
• number of double bonds
• cholesterol

Question 10

how do longer fatty acid chain lengths affect membrane fluidity?

Answer 10

tighter packing of tails, so less fluid

Question 11

how does having more double bonds affect membrane fluidity

Answer 11

looser packing of tails and more fluid