Rate-Determining Enzymes EC

Question 1

Glycolysis rate-determining enzyme and regulators

Answer 1

PFK-1 (phosphofructokinase-1)

+ AMP, fructose 2,6BP
- ATP, citrate

Question 2

Gluconeogenesis rate-determining enzyme and regulators

Answer 2

Fructose-1,6-bisphosphatatse

+ ATP,
- AMP, fructose 2,6BP

Question 3

TCA cycle rate-determining enzyme and regulators

Answer 3

Isocitrate dehydrogenase

+ ADP
- ATP, NADH

Question 4

Glycogen synthesis rate-determining enzyme and regulators

Answer 4

Glycogen synthase

+ Glucose, Insulin
- Epinephrine, Glucagon

Question 5

Glycogenolysis rate-determining enzyme and regulators

Answer 5

Glycogen phosphorylase

+ AMP, Epinephrine, Glucagon
- Insulin, ATP

Question 6

HMP shunt rate-determining enzyme and regulators

Answer 6

G6PD (glucose-6-phosphate dehydrogenase)

+ NADP
- NADPH

Question 7

De novo pyrimidine synthesis rate-determining enzyme and regulators

Answer 7

CMP-II (Carbamoyl phosphate synthetase II)

Question 8

De novo purine synthesis rate-determining enzyme and regulators

Answer 8

Glutamine-PRPP aminotransferase

• AMO, IMP, GMP

Question 9

Urea cycle rate-determining enzyme and regulators

Answer 9

Carbamoyl phosphate synthetase I

+ N-acetylglutamate

Question 10

Fatty acid synthesis rate-determining enzyme and regulators

Answer 10

ACC (Acetyl-CoA Carboxylase)

+ Insulin, Citrate
- Glucagon, palmitoyl-CoA

Question 11

Fatty acid oxidation rate-determining enzyme and regulators

Answer 11

Carnitine acyltransferase I

• Malonyl-CoA

Question 12

Ketogenesis rate-determining enzyme and regulators

Answer 12

HMG-CoA synthase

Question 13

Cholesterol synthesis rate-determining enzyme and regulators

Answer 13

HMG-CoA reductase

+ Insulin, Thyroxine
- Glucagon, Cholesterol