Lipids

Question 1

ketogenic diets reduce ___ in children for unknown reasons

Answer 1

seizures

Question 2

animals can’t convert f.a. into ____

Answer 2

glucose

Question 3

fats are converted into ____ which is then processed by CAC

Answer 3

acetyl coA

Question 4

where does biosynthesis of f.a. occur?

Answer 4

in cytosol

Question 5

intermediates in synthesis pathway involve ____ group of ____

Answer 5

sulfhydryl; ACP (Acyl carrier protein)

Question 6

intermediates in breakdown path involve ___ group of ___

Answer 6

sulfhydryl; Coenzyme A

Question 7

elongation of f.a. stops w/ formation of ____; further elongation uses diff enzymes in ____

Answer 7

palmitate; ER

Question 8

f.a. synthesized by this multienzyme complex:

Answer 8

fatty acid synthase

Question 9

malate to pyruvate is a ___ catalyzed by ___; also makes NADPH required for f.a. synth

Answer 9

decarboxylation; malic enzyme

Question 10

citrate is synthesized in the ____; it is transported to ____ and cleaved by ____ to make acetyl coA

Answer 10

mito; cyto; ATP-citrate lyase

Question 11

to synth palmitate, need __ cycles, and ___ NADPH

Answer 11

7; 14 (2 per cycle)

Question 12

in making palmitate, __ NADPH from malic enzyme, __ from PPP

Answer 12

8; 6

Question 13

name of enzyme that catalyzes 1st (rate limiting) irreversible step of fa biosynth?

Answer 13

acetyl coA carboxylase

Question 14

carboxylase need ___ prosthetic group

Answer 14

biotin

Question 15

coA carboxylase activated by ___ and ___; inhibited by ___, ___ and ___

Answer 15

insulin, citrate; epinephrine, glucagon, palmitate

Question 16

malonyl CoA inhibits ___ which blocks __ oxidation

Answer 16

Carnitine Acyltransferase 1; beta

Question 17

carboxylase is active when ____ and inactive when ___

Answer 17

unphosphorylated; phosphorylated

Question 18

enzyme that turns 2 acetyl coA to acetoacetyl coA

Answer 18

thiolase (or acylCoA acetyltransferase)

Question 19

enzyme that turns acetoacetyl coA to HMG-CoA

Answer 19

HMG-CoA synthase

Question 20

HMG-CoA to acetoacetate enzyme

Answer 20

HMG-CoA lyase

Question 21

for energy purposes, only ___ and ____ used while acetone disappears

Answer 21

acetoacetate; D-3-hydroxybutyrate

Question 22

this molecule is involved in synth of cholesterol and ketone bodies

Answer 22

HMG-CoA

Question 23

levels of f.a. and ketone bodies __ when starvation

Answer 23

increase

Question 24

oxidation of odd chain f.a. require vitamin ____

Answer 24

B12

Question 25

for every db bond, produce __ less FADH2

Answer 25

1

Question 26

probs with db bond oxidation?

Answer 26

need to be on beta C; need be in trans isomer

Question 27

how to activate f.a.?

Answer 27

use 2 ATP to remove glycerol

Question 28

in degradation, 2 C units are sequentially removed from __ end of f.a., producing __ ATP per cycle

Answer 28

carboxyl; 4 (1 FADH2, 1 NADH)

Question 29

voltage dependent channels called ___ move acyl-coA/f.a. across ___ membrane

Answer 29

porins; outer

Question 30

name of protein that transports acyl-carnitine and carnitine

Answer 30

translocase

Question 31

enzyme for carnitine-->acyl-carnitine?

Answer 31

carnitine acyl transferase 1/2

Question 32

acyl binds carnitine just outside the __ membrane, and fatty acids are metabolized in ___ to produce energy

Answer 32

inner; matrix

Question 33

what is beta oxidation?

Answer 33

degradation of f.a. 2 carbons at a time to produce acetyl coA

Question 34

what are the 4 basic steps of beta oxidation?

Answer 34

oxidation, hydration, oxidation, cleavage

Question 35

first step beta-ox?

Answer 35

reduce FAD to create double bond (trans enoyl CoA) using Acyl-CoA dehydrogenase

Question 36

second step beta-ox?

Answer 36

use enoyl CoA Hydratase to split water and turn db bond back to single bond

Question 37

third step beta ox?

Answer 37

use betahydroxyacylCoA dehydrogenase to oxidize to 3-ketoacyl CoA which can be split by addition of another CoA to make 2 acylcoAs

Question 38

4th step beta ox?

Answer 38

thiolysis of acyl-CoA, causing it to connect with acetyl coA to form 3-ketoacyl CoA

Question 39

what are 7 activities that make up f.a. synthase complex?

Answer 39

ACP, AT, KS, MT, KR, HD, ER

Question 40

enzyme that catalyzes attachment of acetyl group to sulfide group on KS

Answer 40

acetyl transacylase (AT)

Question 41

steps in f.a. synthesis?

Answer 41

condensation-->reduction-->dehydration-->reduction

Question 42

step one of f.a. synth is catalyzed by

Answer 42

beta ketoacyl synthase

Question 43

condensation in first step of f.a. synth triggers release of ___ and ___

Answer 43

ACP; CO2

Question 44

enzyme involved with step 2 f.a. synth?

Answer 44

beta-ketoacyl reductase

Question 45

enzyme involved with step 3 f.a. synth?

Answer 45

beta-hydroxyacyl dehydratase

Question 46

enzyme involved with step 4 f.a. synth?

Answer 46

enoyl reductase

Question 47

product of f.a. synth is called ___ and is translocated from ___ to ___

Answer 47

butyryl; ACP; KS

Question 48

free palmitate is released from f.a. synthase complex by ____

Answer 48

hydrolysis

Question 49

elongation of f.a. from palmitate occurs in ___

Answer 49

endoplasmic reticulum (same process as making palmitate)

Question 50

desaturation is catalyzed by ___ enzymes bound to the ____

Answer 50

desaturase; ER

Question 51

essential f.a.s?

Answer 51

linoleate and linolenate

Question 52

necessary for synthesizing prostaglandins, leukotrienes, prostacycline, thromboxanes

Answer 52

arachidonate

Question 53

most common phsopholipid form?

Answer 53

phosphatidylcholine

Question 54

___ catalyzes sequential attachment of f.a. to glycerol backbone via __ bond

Answer 54

acyltransferase; ester

Question 55

1st f.a. chain is usually ___ while middle one is ____

Answer 55

saturated; unsaturated

Question 56

name of enzyme that converts phosphatidate to DAG

Answer 56

phosphatidate phosphatase

Question 57

triacyl/phospho synth in ___

Answer 57

liver

Question 58

diacylglycerol is activated by ____

Answer 58

CTP (form CDP-diacylglycerol)

Question 59

CDP-DAG rxt w/ ___ to form phospholipid

Answer 59

alcohol

Question 60

alcohol is activated by ___ and reaction with ___ to form CDP-alcohol

Answer 60

phosphorylation; CTP

Question 61

activated alcohol rxt w/ ___ to form phospholipid

Answer 61

diacylglycerol

Question 62

name of enzyme from ethanolamine to phosphorylethanolamine

Answer 62

ethanolamine kinase

Question 63

if choline is deficient, phosphatidylcholine can be synth from phophatidylethanolamine by ___ with ____

Answer 63

methylation; SAM (S-adenosylmethionine)

Question 64

cholesterol is synth especially in __

Answer 64

liver

Question 65

function of chol:

Answer 65

structure in membrane, precursor of bile salts, steroids, vit. D

Question 66

chol have __ carbons, all C come from ____

Answer 66

27; acetyl coA

Question 67

4 stages of chol synth, 1+2 in __, 3+4 in ___

Answer 67

cyto; ER

Question 68

1st product in chol synth?

Answer 68

mevalonate (6C)

Question 69

mevalonate is converted to ___

Answer 69

isoprene (5C)

Question 70

isoprene is converted to ___ through ___

Answer 70

squalene (30C); condensation

Question 71

HMG-CoA is converted to mevalonate through ___ reaction, by ___ enzyme

Answer 71

reduction; HMG CoA reductase

Question 72

3 fates of chol:

Answer 72

hepatocyte plasma membrane, storage, exported through blood-->tissues

Question 73

storage form of chol:

Answer 73

cholesterol ester

Question 74

complexes of proteins and lipids that transport TAG and chol in blood

Answer 74

lipoproteins

Question 75

4 components of lipoproteins

Answer 75

unesterified chol, phospholipid, chol ester, apoprotein B-100

Question 76

___ and ___ transport chol, ___ and __ transport TAG

Answer 76

HDL; LDL; VLDL; chylomiciron

Question 77

least dense lipoprotein is :

Answer 77

chylomicron

Question 78

condition involving very high circulating chol lvls, severe atherosclerosis, defective LDL receptor

Answer 78

familial hypercholesterolemia

Question 79

how to treat familial hypercholesterolemia?

Answer 79

statins (competitive inhibitors of HMG CoA)