Biochem High Yield Enzymes

Question 1

What is the rate determining enzyme of glycolysis?

Answer 1

Phosphofructokinase

Question 2

What are the positive regulators of Phosphofructokinase?

Answer 2

AMP, Fructose2,6,biphosphate

Question 3

What are the negative regulators of Phosphofructokinase?

Answer 3

ATP, citrate

Question 4

What is the rate determining enzyme of gluconeogenesis?

Answer 4

Fructose-1,6-biphosphatase

Question 5

What are the positive regulators of Fructose-1,6-biphosphatase?

Answer 5

ATP, acetyl-CoA

Question 6

What are the negative regulators of Fructose-1,6-biphosphatase?

Answer 6

AMP, fructose-2,6-biphosphate

Question 7

What is the rate determining enzyme of TCA cycle?

Answer 7

Isocitrate dehydrogenase

Question 8

What are the positive regulators of isocitrate dehydrogenase?

Answer 8

ADP

Question 9

What are the negative regulators of isocitrate dehydrogenase?

Answer 9

ATP, NADH

Question 10

What is the rate determining enzyme of glycogenesis?

Answer 10

dephosphorylated Glycogen synthase

Question 11

What are the positive regulators of Glycogen synthase?

Answer 11

Glucose 6 Phosphate, insulin, cortisol

Question 12

What are the negative regulators of Glycogen synthase?

Answer 12

Epi, glucagon

Question 13

What is the rate determining enzyme of glycogenolysis?

Answer 13

Glycogen phosphorylase

Question 14

What are the positive regulators of glycogen phosphorylase?

Answer 14

Epi, glucagon, AMP

Question 15

What are the negative regulators of glycogen phosphorylase?

Answer 15

glucose-6-phosphate, insulin, ATP

Question 16

What is the rate determining enzyme of HMP shunt?

Answer 16

Glucose-6-phosphate dehydrogenase

Question 17

What are the positive regulators of Glucose-6-phosphate dehydrogenase?

Answer 17

NADP+

Question 18

What are the negative regulators of Glucose-6-phosphate dehydrogenase?

Answer 18

NADPH

Question 19

What is the rate determining enzyme of de novo pyrimidine synthesis?

Answer 19

Carbamoyl phosphate synthetase II

Question 20

What are the positive regulators of Carbamoyl phosphate synthetase II?

Answer 20

ATP

Question 21

What are the negative regulators of Carbamoyl phosphate synthetase II?

Answer 21

UTP

Question 22

What is the rate determining enzyme of de novo purine synthesis?

Answer 22

Glutamine-phophoribosylpyrphosphate aminotransferase

Question 23

What are the negative regulators of Glutamine-phophoribosylpyrphosphate aminotransferase?

Answer 23

AMP, IMP, GMP

Question 24

What is the rate determining enzyme of the urea cycle?

Answer 24

Carbamoyl phosphate synthetase I

Question 25

What are the positive regulators of Carbamoyl phosphate synthetase I?

Answer 25

N-acetylglutamate

Question 26

What is the rate determining enzyme of fatty acid synthesis?

Answer 26

Acetyl-CoA carboxylase

Question 27

What are the positive regulators of Acetyl-CoA carboxylase?

Answer 27

Insulin, citrate

Question 28

What are the negative regulators of Acetyl-CoA carboxylase?

Answer 28

glucagon, palmitoyl-CoA

Question 29

What is the rate determining enzyme of fatty acid oxidation?

Answer 29

Cartinitine acyltransferase I

Question 30

What are the negative regulators of Cartinitine acyltransferase I?

Answer 30

Malonyl-CoA

Question 31

What is the rate determining enzyme of ketogenesis?

Answer 31

HMG-CoAse

Question 32

What is the rate determining enzyme of cholesterol synthesis?

Answer 32

HMG-CoA reductase

Question 33

What are the positive regulators of HMG-CoA reductase?

Answer 33

Insulin, thyroxine

Question 34

What are the negative regulators of HMG-CoA reductase?

Answer 34

Glucagon, cholesterol

Question 35

What does protein phosphatase-1 do in hepatocytes?

Answer 35

Activated downstream from insulin --> tyrosine kinase --> etc. Protein phosphatase dephosphorylates Fructose1,6-phosphate and glycogen synthase, thus halting gluconeogenesis and ACTIVATING glycogen synthase.