2.6 Lecture

Question 1

Saturated fatty acids

Answer 1

-Have no double bonds in the acyl chain
-pack tightly to form crystalline layers
-long chains = more interactions = higher melting point

Question 2

Unsaturated fatty acids

Answer 2

-Have double bonds in acyl chain
-makes a kink in the chain that prevents tight packing
-more double bonds = more bends = less/weak interactions = lower melting point

Question 3

What are the 3 parts of a lipid?

Answer 3

1. polar head group
2. hydrophobic fatty acid tails
   3.backbone that connects head and tail

Question 4

Phospholipids

Answer 4

have a phosphorylated head group

Question 5

glycolipids

Answer 5

have sugar/polysaccharide head group

Question 6

Glycerophospholipids

Answer 6

-Glycerol backbone, –phosphorylated
head group (C3)
-two fatty acid tails, mostly ester linkages
-3 carbons in back bone

Question 7

Galactolipids and sulfolipids

Answer 7

-Glycerol backbone
-head group = galactose
-no phosphate in head group
-two fatty acid tails
-important for plants (found in thylakoid/chloroplasts)

Question 8

Archaeal tetraether lipids:

Answer 8

-Two very long alkyl chains are
ether linked to a glycerol at both ends (4 ether links = tetra ether)
-lipid MONOLAYER

Question 9

Sphingolipids:

Answer 9

-amino alcohol with long acyl chain
-amino alcohol = backbone not glycerol
-2 hydrocarbon tails but 1 is already on sphingosine
-amide linkage

Question 10

Sterols

Answer 10

rigid systems of four fused hydrocarbon rings
-somewhat amipathic due to small head group and nonpolar hydrocarbon body`

Question 11

Sphingomyelins

Answer 11

Phosphorylated head groups of sphingolipids
-found in mammalian cell membrane

Question 12

Glycosphingolipids

Answer 12

Sugar head groups of sphingolipids

Question 13

Gangliosides

Answer 13

Sialic acid head group
-2+ sugars
-negative

Question 14

Cerebrosides

Answer 14

1 sugar
-neutral

Question 15

Globosides

Answer 15

2+ sugars
-neutral

Question 16

Conical lipids

Answer 16

pack into micelles

Question 17

cylindrical lipids

Answer 17

pack into bilayers

Question 18

below physiological temperatures

Answer 18

-lipid bilayers are in a solid state
-motion is constrained

Question 19

above physiological temperatures

Answer 19

-membrane bilayers go from liquid ordered state to disordered state

Question 20

To tolerate high temperatures

Answer 20

-membranes need less fluidity
-longer fatty acids and saturated