exam 2 enzymes

Question 1

glycogen phosphorylase is involved in what function?

Answer 1

glycogen degradation, and needs PLP (b6)

Question 2

phosphorylase kinase is involved in what function?

Answer 2

turning on and off glycogen synthase

Question 3

methionine synthase is involved in what function?

Answer 3

cysteine synthesis. (this is why cysteine isn’t an essential amino acid)

Question 4

glycoxylate transaminase is involved in what function?

Answer 4

glucogenic degradation of glycine. if defective, you get kidney stones

Question 5

aspartate transaminase is involved in what function?

Answer 5

amino acid catabolism (transamination of alpha amino group)

Question 6

acetyl CoA carboxylase is involved in what function?

Answer 6

regulated step of fatty acid synthesis

Question 7

HMG-CoA reductase is involved in what function?

Answer 7

regulated step of cholesterol synthesis

Question 8

glut 4

Answer 8

in fat, muscle, heart

Question 9

CETP is involved in what function?

Answer 9

transfer of cholesterol from HDL to VLDL

Question 10

biotinidase is involved in what function?

Answer 10

lipid synthesis. Biotin for acetyl CoA carboxylase

Question 11

Kynurenine hydroxylase is involved in what function?

Answer 11

tryptophan degradation, maybe also to make NAD. PLP dependent, so use this to test for PLP deficiency

Question 12

methylmalonyl CoA mutase is involved in what function?

Answer 12

breaking down propionoyl CoA to succinyl CoA for TCA cycle. needs vitamin B12

Question 13

pancreatic lipase is involved in what function?

Answer 13

digestion of lipids; frees 2 fatty acids by cleaving at 1 and 3 of triacyglycerol

Question 14

phospholipase A2 is involved in what function?

Answer 14

usually for prostaglandin synthesis; cleaves FA at second position

Question 15

fatty acid synthase complex is involved in what function?

Answer 15

makes fatty acid from malonyl CoA to palmitate after 6 cycles. (1 cycle is on SCRDR and uses 2 NADPH and 1 water)

Question 16

glucoamylase is involved in what function?

Answer 16

carbohydrate digestive enzyme (cleaves 1,4 glycosidic bonds)

Question 17

G-6-P DH is involved in what function?

Answer 17

pentose phosphate pathway; makes NADPH

Question 18

serine protease is involved in what function?

Answer 18

extracellular proteolysis of proteins; example = collagenase

Question 19

glutamate DH is involved in what function?

Answer 19

oxidative deamination of proteins; makes glutarate and ammonium

Question 20

CYP7A1 is involved in what function?

Answer 20

bile synthesis; puts an -OH on C7 using oxygen and NADPH

Question 21

UDP glucose pyrophosphorylase is involved in what functions?

Answer 21

galactose metabolism; glycogen synthesis; bilirubin, UDP glucuronic acid

Question 22

what is the main regulatory enzyme and allosteric effectors of glycogenesis?

Answer 22

glycogen synthase; + G6P

Question 23

what is the main regulatory enzyme and allosteric effectors of glycogenolysis

Answer 23

glycogen phosphorylase; + Ca++ in muscle, glucagon in liver

Question 24

what is the main regulatory enzyme and allosteric effectors of pentose phosphate pathway

Answer 24

glucose 6 phosphate DH; -NADPH

Question 25

what is the main regulatory enzyme and allosteric effectors of fatty acid synthesis?

Answer 25

acetyl CoA carboxylase; +citrate +insulin -palmitate - glucagon

Question 26

what is the main regulatory enzyme and allosteric effectors of lipolysis?

Answer 26

hormone-sensitive lipase; +epinepherine -insulin

Question 27

what is the main regulatory enzyme and allosteric effectors of cholesterol synthesis?

Answer 27

HMG CoA reductase; - cholesterol + insulin - glucagon

Question 28

what is the main regulatory enzyme and allosteric effectors of urea cycle?

Answer 28

Carbamoyl phosphate synthetase (CPS1); + NAG