Ch 5: Lipid Structure and Function

Question 1

lipids are soluble in

Answer 1

nonpolar organic solvents

Question 2

the head group of phospholipids are attached by a ____ and bc it interacts with the environment, determines the function of the phospholipid

Answer 2

phosphodiester linkage

Question 3

saturated fatty acids are ____ fluid than unsaturated

Answer 3

less

Question 4

phospholipids that contain a glycerol backbone

Answer 4

glycerophospholipids

Question 5

_____ contain a sphingosine backbone; many but not all are also phospholipids with a phosphodiester bond; these are called ____

Answer 5

Sphingolipids

Sphingophospholipids

Question 6

Sphingomyelins

Answer 6

are the major class of sphingophospholipids and contain a phosphatidylcholine or phosphatidylethanolamine head group. they are the major contributer in the myelin sheath

Question 7

_____ attached to sugar moieties instead of a phosphate group. ____ have one sugar connected to sphingosine; ____ have two or more

Answer 7

glycosphingolipids

cerebrosides
globosides

Question 8

gangliosides

Answer 8

contain oligosaccharides with at least one terminal N-acetylneuraminic acid (NANA; also called sialic acid)

Question 9

waxes contain long-chain fatty acids that are ___ to long chain alcohols

Answer 9

esterfied

Question 10

terpenes

Answer 10

odiferous steroid precursors from isoprene, a five carbon molecule

Question 11

one terpene unit (a monoterpene) contains

Answer 11

2 isoprene units

Question 12

terpenoids are derived from terpenes via

Answer 12

oxygenation or backbone rearrangement. they have similar odorous characteristics

Question 13

Steroids

Answer 13

contain three cyclohexane rings and one cylcopentane ring

oxidation state and functional group may vary

Question 14

steroid hormones have

Answer 14

high-affinity receptors, work at low concentrations and affect gene expression and metabolism

Question 15

cholesterol is a

Answer 15

steroid hormone important to membrane fluidity and stability; it serves as a precursor to a host of other molecules

Question 16

____ are autocrine and paracrine hormones that regulate cAMP levels. they have powerful effects on muscle contraction, body temp, the sleep-wake cycle, and pain

Answer 16

Postaglandins

Question 17

fat-soluble vitamins include

Answer 17

A,K,E,D

Question 18

Vit A (carotene) is

Answer 18

metabolized to retinal for vision and retinoic acid for gene expression in epithelial development

carotene - carrots are high in vit A eat to improve vision

Question 19

Vit D (cholecalciferol) is metabolized to

Answer 19

calcitriol in the kidneys and regulates calcium and phosphorus homeostasis in the intestines (inc ca and phosphate absorption), promoting bone formation. deficiency of this causes rickets

D regulates calcium, remember it is freq added to milk to aid in absorption of calcium

Question 20

Vit E (tocopherols)

Answer 20

act as biological antioxidants. their aromatic rings destroy free radicals, preventing oxidative damage

Question 21

Vit K (phylloquinone and menaquinones)

Answer 21

important for formation of prothrombin, a clotting factor. performs posttranslational modifications on a number of proteins, creating calcium binding sites

vit k is for koagulation

Question 22

preferred method of storing energy for long-term use

they contain one glycerol attached to 3 fatty acids by ester bonds
very hydrophobic so not hydrated by water in body and therefore do not carry extra weight

Answer 22

triacylglycerols (triglycerides)

Question 23

carbon atoms in ____ are more reduced than ___ , giving twice as much energy per gram during oxidation

Answer 23

lipids

carbohydrates

Question 24

animal cells specifically used for storage of large triacylglycerol deposits are called

Answer 24

adipocytes

Question 25

free fatty acids are

Answer 25

unesterfied fatty acids that travel through the bloodstream

Question 26

salts of free fatty acids are ____ and can be synthesized in saponification

Answer 26

soaps

Question 27

saponification

Answer 27

is the ester hydrolysis of triacylglycerols using a strong base, like Na or KOH

Question 28

Micelles can dissolve a ___ in its fatty acid core, and washes away with water bc of its shell of ___ head groups

Answer 28

lipid-soluble molecule

carboxylate