Regulatory Enzymes of Metabolism

Question 1

Glycolysis

Answer 1

Pyruvate Kinase

PFK-1

Activate: AMP, Fructose-2,6-Bisphosphate

Inhibit: ATP, Citrate

Question 2

Gluconeogenesis

Answer 2

Fructose-1,6-Bisphosphate

Activate: Citrate

Inhibit: AMP, Frustose-2,6-Bisphosphate

Question 3

Citric Acid Cycle

(TCA, Kreb’s)

Answer 3

Citrate Synthase

(Acetyl-CoA + OAA => Citrate)

Activate: High [OAA], ADP

Inhibit: Low [OAA], ATP, NADH

Question 4

Glycogenesis

Answer 4

Glycogen Synthase

Activate: Glucose-6-Phosphate, Insulin, Cortisol

Inhibit: Glucagon, Epinephrine

Question 5

Glycogenolysis

Answer 5

Glycogen Phosphorylase

Activate: Glucagon, Epinephrine, AMP

Inhibit: Glucose-6-Phosphate, Insulin, ATP

Question 6

Pentose Phosphate Pathways

Answer 6

Glucose-6-Phosphate Dehydrogenase (G6PD)

Activate: NADP+

Inhibit: NADPH

Question 7

Urea Cycle

Answer 7

Carbamoyl Phosphate Synthetase (CPS-1)

Activate: N-acetyl Glutamate, Arginine

Question 8

Fatty Acid Synthesis

Answer 8

Acetyl CoA Carboxylase

(Malonyl CoA presence)

Activate: Insulin, Citrate

Inhibit: Glucagon, Palmitoyl-CoA

Question 9

Fatty Acid Oxidation

Answer 9

Carnitine Acetyl Transferase I (CPT-1)

Activate:

Inhibit: Malonyl CoA (first product of synthesis)

Question 10

Ketogenesis

Answer 10

HMG-CoA Synthase

Question 11

Cholesterol Synthesis

Answer 11

HMC-CoA Reductase

Activate: Insulin, Thyroxine

Inhibit: Glucagon, Epinephrine, Statins, High Cholesterol (block transcription), AMPK

Question 12

Heme Synthesis

Answer 12

ALA-Synthase

Activate: Low Hemin

Inhibit: High Hemin

Question 13

Catecholamines

Answer 13

THB