Lipids

Question 1

What is a glycolipid or glycosphingolipid?

Answer 1

sphingolipid with a sugar head group

Question 2

what’s the difference between cerebrosides and globosides?

Answer 2

both are sphingolipids, but cerebrosides have 1 sugar and globosides have two or more sugars

since the head groups are sugars, they have no net charge - ie. neutral glycolipids

Question 3

What are gangliosides?

Answer 3

a glycosphingolipid but with a NANA/sialic acid on the head group
these are very large (gangly) and complex

Question 4

what type of membrane lipid is a sphingomyelin, and what types of cell’s membranes are they common in?

Answer 4

sphingomyelin is a sphingophospholipid

sphingomyelin is common in myelin producing cells (oligodendrocytes and schwann cells)

Question 5

what type of lipid on a RBC membrane indicates blood type?

Answer 5

sphingolipid

Question 6

A single terpene contains how units of which chemical moiety?

Answer 6

a single terpene contains two isoprene units

Question 7

terpenes and terpenoids form what type of signalling lipid?

Answer 7

steroids

Question 8

a steroid is defined by how many cycloalkane rings fused together?

Answer 8

4 cycloalkane rings fused together

3 cyclohexanes, 1 cyclopentase

Question 9

bile acid, vitamin D, and steroid hormones are derivatives of what lipid?

Answer 9

cholesterol, a steroid

Question 10

what signalling lipid regulates the synthesis of cAMP? structurally, it is derived from arachidonic acid, has 20 carbons, and has a 5-carbon ring

Answer 10

prostoglandins

Question 11

what are four lipid soluble vitamins?

Answer 11

ADEK

Question 12

Vitamin A is important for what function?

Answer 12

vision; retinal is a derivative of Vitamin A

carrots –> carotene (aka. Vitamin A)

Question 13

Vitamin D is important for what function?

Answer 13

bone growth and calcium regulation; Vitamin D is added in milk to increase calcium (and phosphate) absorption in intestines

can be formed by UV light driven reaction

Question 14

Vitamin E is important for what function?

Answer 14

antioxidant

Question 15

Vitamin K is important for what function?

Answer 15

coagulation; necessary for prothrombin formation

also creates calcium binding sites in proteins

Question 16

what are fatty acids better for energy storage than sugars? (3 reasons)

Answer 16

1. more energy dense: when oxidized fatty acids yield more energy since they are more reduced than carbs
2. not water soluble so weigh less: carbs require hydration for stability and therefore weigh more
3. insulation

Question 17

what is saponification?

Answer 17

formation of soaps

specifically, it is the ester hydrolysis of triacylglycerols into glycerol and salt fatty acids using a strong base