Lipid Structure and Function

Question 1

Amphipathic

Answer 1

Hydrophobic and hydrophilic regions

Question 2

Phospholipid polar and nonpolar parts

Answer 2

Polar head is the phosphate and alcohol and it is attached to hydrophobic fatty acids by phosphodiester bonds

Question 3

Saturated fatty acid

Answer 3

Has no pi bonds and is stable and solid at room temperature

Question 4

Unsaturated fatty acid

Answer 4

Has pi bond(s) which result in kinks and make it a liquid at room temperature

Question 5

Glycerophospholipid

Answer 5

• Has glycerol backbone
• Ester linkages to two fatty acids (can vary in length) and phosphodiester links to highly polar group which determines chemistry

Question 6

Sphingolipids

Answer 6

-Have sphingolipid backbone

Question 7

Glycolipid

Answer 7

Lipid linked to sugar

Question 8

Ceramide

Answer 8

Sphingolipid with hydrogen atom at its head group

Question 9

Sphingomyelins

Answer 9

• Sphingolipids
• Phosphotidylcholine or phosphotidylethanolamine
• no net charge
• major part of schwaan and oligodendrocytes’ plasma membranes

Question 10

Glycosphingolipids

Answer 10

Instead of phosphodiester bonds to polar groups, thers is glycosidic bonds to sugar groups

Question 11

Cerebrosides

Answer 11

Sphingolipids attached to 1 sugar

Question 12

Globosides

Answer 12

Sphingolipids attached to 2 or more sugars

Question 13

Gangliosides

Answer 13

Glycolipids with NANA at end terminus and a negative charge

Question 14

Waxes

Answer 14

Esters of long-chain fatty acids with long-chain alcohols, solid at room temp, prevent evaporation and dehydration

Question 15

Terpenes

Answer 15

Precursors to lipid signaling molecules; built from isoprene C5H8
|
// \ //

Question 16

Monoterpene

Answer 16

C10H16

has two isoprene units

Question 17

Sesquiterpene

Answer 17

3 isoprene units

C15H24

Question 18

Terpenoids/isoprenoids

Answer 18

Oxidized or rearranged terpenes and modified with a functional group
- Aromatic

Question 19

Diterpenoid

Answer 19

Has 4 isoprene units

Question 20

Steroids

Answer 20

Have 4 cycloalkane rings: 3 cyclohexane and 1 cyclopentane

-Oxidized states and functional groups vary

Question 21

Steroid hormones

Answer 21

Hormones that are steroids

Question 22

Cholesterol

Answer 22

• Amphipathic and in phospholipid bilayer
• Low temp => prevents soldification
• High temp => keeps membrane intact
• precursor to other molecules

Question 23

Prostaglandins

Answer 23

• Para- or autocrine signaling molecules
• regulate cAMP
• Effects on smooth muscle function, sleep/wake cycle, and body temperature

Question 24

Vitamin

Answer 24

Essential nutrient

Question 25

Vitamin A/Carotene

Answer 25

- Retinal is component of light sensor in eye | - Retinol stores vitamin A and is oxidized to retinoic acid to regulate gene expression during epithelial development

Question 26

Retinal

Answer 26

Component of light sensor in eye

Question 27

Retinol

Answer 27

Stores vitamin A

Question 28

Retinoic acid

Answer 28

Oxidized form of retinol and regulates gene expression of epithelial development

Question 29

Vitamin D/cholecalciferol

Answer 29

It is turned into calcitriol by the liver and kidneys which in turn upregulates calcium and phosphate uptake to promote bone production

Question 30

Rickets

Answer 30

Lack vitamin D and leads to underdeveloped bones and impeded growth

Question 31

Vitamin E

Answer 31

- Tocopherols and tocotrienols - have aromatic rings that destory free radicals - antioxidants

Question 32

Vitamin K

Answer 32

- Phylloquinone and menaquiones - Required to form prothrombin, clotting factors - Posttranslational modifications to make calcium binding sites

Question 33

Why are fats more efficient at storing energy than sugars?

Answer 33

1. Lipids are more reduced than sugars and so their oxidation yields more energy 2. Triacylglycerols are hydrophobic; does not draw water and don't need it for stability (no additional weight)

Question 34

Triacylglycerol

Answer 34

3 fatty acids bonded by ester linkages to a glycerol, nonpolar, nonsoluble in water

Question 35

Adipocytes

Answer 35

Cells that store large amount of fat

Question 36

Free fatty acids

Answer 36

Are unesterified fatty acids with a free carboxylate group

Question 37

Saponification

Answer 37

Ester hydrolysis using a strong base (NaOH or KOH). Products are fatty acid salts or soaps.

Question 38

Surfactants

Answer 38

- Can be soaps | - lower surface tension and form micelles to dissolve both polar and nonpolar to make colloids