Lipids

Question 1

How does chain length affect MP of fatty acids?

Answer 1

longer chain=higher melting point

Question 2

How does unsaturation affect MP of fatty acids?

Answer 2

more unsaturation=lower melting point

Question 3

Which end of a fatty acid is the delta end? Omega?

Answer 3

delta=carboxylic acid end

omega=hydrocarbon end

Question 4

What are waxes?

Answer 4

mono esters of long-chained alcohols and fatty acids

Question 5

What is Claisen condensation reaction?

Answer 5

a N nucleophilic acyl substitution reaction using carbanions to form new C-C bonds

Question 6

What are two modifications to Claisen condensation reactions in biological systems?

Answer 6

thioesters are used because they are more electrophilic and RS- is a better leaving group (than RO-)
decarboxylation of malonyl thioesters are used as carbanion equivalents

Question 7

What is Michael addition?

Answer 7

the addition of a nucleophile to the beta-carbon of an alpha,beta-unsaturated carbonyl

Question 8

What are soaps?

Answer 8

the metal salts of fatty acids

Question 9

How are soaps prepared?

Answer 9

by the hydrolysis of triglycerides

Question 10

What are detergents?

Answer 10

contain a hydrophilic head that is not a carboxylate group so they don’t precipitate out of solution in the presence of polyvalent ions

Question 11

What is usually found in a cationic detergents?

Answer 11

quaternary ammonium slats

Question 12

What kind of head is found on non-ionic detergents?

Answer 12

hydrophilic heads that don’t have any formal charge

Question 13

Name two additives found in detergents

Answer 13

phosphates and silicates

Question 14

What is a phospatidic acid?

Answer 14

glycerol with two fatty acids and a phosphate

Question 15

What is a phospholipid?

Answer 15

phosphatidic acid with an alcohol esterfied to the phosphate

Question 16

Describe the structure of prostanoic acid

Answer 16

C7 carboxylic acid chain
cyclopentane ring
C8 chain

Question 17

What can be made from arachidonic acid?

Answer 17

prostaglandins and leukotrines

Question 18

How are prostaglandins made from arachidonic acid?

Answer 18

oxidation of it

Question 19

How are leukotrines made from arachidonic acid?

Answer 19

epoixdation of it (using 5-lipoxygenase)

Question 20

What is a terpene with 10C called?

Answer 20

monoterpene

Question 21

What is a terpene with 15C called?

Answer 21

sesquiterpene

Question 22

What is a terpene with 20C called?

Answer 22

diterpene

Question 23

What is a terpene with 25C called?

Answer 23

sesterterpene

Question 24

What is a terpene with 30C called?

Answer 24

triterpene

2 sesquiterpenes linked T to T

Question 25

What is a terpene with 40C called?

Answer 25

tetraterpene

2 diterpenes linked T to T

Question 26

What 4 things need to happen to turn the aldol condensation product to IPP-OPP? What is this pathway called?

Answer 26

1) extra C attached to one head needs to be lost
2) tail needs to be reduced to alcohol then protonated
3) OH on neck needs to be removed
4) double bond between the neck and head needs to be made
Called the mevalonic acid pathway

Question 27

What are steroids synthesized from?

Answer 27

terpenes

Question 28

What are steroids?

Answer 28

4 rings

3 six-membered, 1 5-membered

Question 29

What are the fat-soluble vitamins?

Answer 29

A, D, E and K

Question 30

What is another name for vitamin A?

Answer 30

retinol

Question 31

How is vitamin A used in the body?

Answer 31

In rod cells
is oxidized to retinal 
converted trans to cis to fit into opsin 
light changes it back to trans
leaves opsin

Question 32

Is vitamin E a true terpene?

Answer 32

no

Question 33

How is vitamin E used in the body?

Answer 33

has a phenolic OH that can be lost and it is then an antioxidant