Metabolic Process/Rate-limiting enzyme and its regulators

Question 1

Glycolysis

Answer 1

Phosphofructokinase-1 (PFK-1)
+ve AMP and fructose-2,6-bisphosphate
-ve ATP and citrate

Question 2

Gluconeogenesis

Answer 2

Fructose-1,6-bisphosphatase

-ve AMP and fructose-2,6-bisphosphate

Question 3

TCA

Answer 3

Isocitrate dehydrogenase
+ve ADP
-ve ATP and NADH

Question 4

Glycogenesis

Answer 4

Glycogen synthase
+ve Glucose-6-phosphate, insulin and cortisol
-ve Epinephrine and glucagon

Question 5

Glycogenolysis

Answer 5

Glycogen phosphorylase
+ve Epinephrine, glucagon and AMP
-ve Glucose-6-phosphate, insulin and ATP

Question 6

HMP shunt

Answer 6

Glucose-6-phosphate dehydrogenase (G6PD)
+ve NADP+
-ve NADPH

Question 7

De novo pyrimidine synthesis

Answer 7

Carbamoyl phosphate synthetase II
+ve ATP and PRPP
-ve UTP

Question 8

De novo purine synthesis

Answer 8

Glutamine-phosphoribosylpyrophosphate (PRPP) amidotransferase
-ve AMP, inosine monophosphate (IMP) and GMP

Question 9

Urea cycle

Answer 9

Carbamoyl phosphate synthetase I

+ve N-acetylglutamate

Question 10

Fatty acid synthesis

Answer 10

Acetyl-CoA carboxylase (ACC)
+ve Insulin and citrate
-ve Glucagon and palmitoyl-CoA

Question 11

Fatty acid oxidation

Answer 11

Carnitine acyltransferase I

-ve Malonyl-CoA

Question 12

Ketogenesis

Answer 12

HMG-CoA synthase

Question 13

Cholesterol synthesis

Answer 13

HMG-CoA reductase
+ve Insulin and thyroxine
-ve Glucagon and cholesterol