Rate limiting enzymes of metabolic processes

Question 1

glycolysis

Answer 1

phosphofructokinase 1
enhanced by AMP, fructose-2,6-bisphosphate
inhibited by ATP, citrate

Question 2

gluconeogenesis

Answer 2

fructose-1,6-bisphosphate

enhanced by ATP, Acetyl CoA

Question 3

TCA cycle

Answer 3

isocitrate dehydrogenase

enhanced by ATP
inhibited by AMP, fructose-2,6-bisphosphate

Question 4

Glycogenesis

Answer 4

glycogen synthase

enhanced by glucose-6-phosphate, insulin, cortisol
inhibited by epinephrine, glucagon

Question 5

Glycogenolysis

Answer 5

glycogen phosphorylase

enhanced by epinephrine, glucagon, AMP
inhibited by glucose-6-phosphate, insulin, ATP

Question 6

HMP shunt

Answer 6

glucose- 6- phosphate dehydrogenase (G6PD)

enhanced by NADP
inhibited by NADPH

Question 7

De novo pyrimidine synthesis

Answer 7

Carbamoyl phosphate synthetase II

Question 8

De novo purine synthesis

Answer 8

Glutamine- phosphoribosylpyrophosphate (PRPP) amidotransferase
inhibited by AMP, inosine monophosphate (IMP), GMP

Question 9

urea cycle

Answer 9

carbamoyl phosphate synthetase I

enhanced by N- acetylglutamate

Question 10

fatty acid synthesis

Answer 10

acetyl- coA carboxylase (ACC)

enhanced by insulin, citrate
inhibited by glucagon, palmotoyl- CoA

Question 11

fatty acid oxidation

Answer 11

carnitine acyltransferase I

inhibited by malonyl CoA

Question 12

Ketogenesis

Answer 12

HMG CoA Synthase

Question 13

Cholesterol synthesis

Answer 13

HMG CoA reductase

enhanced by insulin, thyroxine
inhibited by glucagon, cholesterol

Question 14

bile acid synthesis

Answer 14

7-alpha-hydroxylase

Question 15

heme synthesis

Answer 15

aminolevulinate synthase