Biochem

Question 1

Rate-limiting enzyme of glycolysis

Answer 1

PFK-1 (+ by AMP and F-2,6-BP; - by ATP and citrate)

Question 2

rate limiting enzyme of gluconeogenesis

Answer 2

F-1,6-BP

+ by ATP, acetyl CoA; - by AMP, F-2,6-BP

Question 3

rate limiting enzyme of TCA cycle

Answer 3

isocitrate dehydrogenase

+ by ADP; - by ATP and NADH

Question 4

RLE of glycogenesis

Answer 4

glycogen synthase

+ by G6P, insulin, cortisol; - by Epi, glucagon

Question 5

RLE of glycogenolysis

Answer 5

glycogen phosphorylase
(+ by Epi, glucagon, AMP)
(- by G6P, insulin, ATP)

Question 6

RLE of HMP shunt

Answer 6

G6PD

+ by NADP+, - by NADPH

Question 7

RLE of de novo pyrimidine synthesis

Answer 7

carbamoyl phosphate synthetase II

Question 8

RLE of de novo purine synthesis

Answer 8

glutamine phosphoribosylpyrophosphate (PRPP) amidotransferase
(- by AMP, IMP, GMP)

Question 9

RLE of urea cycle

Answer 9

carbamoyl phosphate synthetase I

+ by N-acetylglutamate

Question 10

RLE of fatty acid synthesis

Answer 10

Acetyl-CoA carboxylase
+ by insulin, citrate
- by glucagon, palmitoyl-CoA

Question 11

RLE of fatty acid oxidation

Answer 11

carnitine acyltransferase I (- by malonyl CoA)

Question 12

RLE of ketogenesis

Answer 12

HMG-CoA synthase

Question 13

RLE of CH synthesis

Answer 13

HMG-CoA reductase
(+ by insulin, thyroxine)
(- by glucagon, cholesterol)

Question 14

derivatives of phenylalanine

Answer 14

Phe –> Tyrosine –> DOPA –> DA –> NE –> E

Question 15

derivatives of tryptophan

Answer 15

Trp –> Niacin –> NAD+/NADP+

Trp –> SE –> Melatonin

Question 16

derivatives of histidine

Answer 16

Histidine –> histamine

Question 17

derivatives of glycine

Answer 17

Glycine –> Porphyrin –> Heme

Question 18

derivatives of glutamate

Answer 18

Glutamate –> GABA

Glutamate –> Glutathione

Question 19

derivatives of arginine

Answer 19

Arginine –> Creatinine, Urea, NO