Metabolism

Question 1

Rate determining enzyme of glycolysis

Answer 1

Phosphofructokinase-1 (PFK-1)

Question 2

Rate determining enzyme of gluconeogenesis

Answer 2

Fructose-1,6-bisphosphate

Question 3

Rate determining enzyme of TCA Cycle

Answer 3

Isocitrate dehydrogenase

Question 4

Rate determining enzyme of glycogenesis

Answer 4

Glycogen synthase

Question 5

Rate determining enzyme of glycogenolysis

Answer 5

Glycogen phosphorylase

Question 6

Rate determining enzyme of pentose phosphate pathway

Answer 6

Glucose-6-phosphate dehydrogenase (G6PD)

Question 7

Rate determining enzyme of de novo pyrimidine synthesis

Answer 7

carbamoyl phosphate synthetase II

Question 8

Rate determining enzyme of de novo purine synthesis

Answer 8

glutamine-phosphoribosylpyrophosphate (PRPP) amidotransferase

Question 9

Rate determining enzyme of urea cycle

Answer 9

carbamoyl phosphate synthetase I

Question 10

Rate determining enzyme of fatty acid synthesis

Answer 10

Acetyl-CoA Carboxylase (ACC)

Question 11

Rate determining enzyme of fatty acid oxidation

Answer 11

Carnitine acyltransferase I

Question 12

Rate determining enzyme of ketogenesis

Answer 12

HMG-CoA Synthase

Question 13

Rate determining enzyme of cholesterol synthesis

Answer 13

HMG-CoA Reductase

Question 14

What do NADH, NADPH, and FADH2 carry?

Answer 14

electrons

Question 15

What do CoA and lipoamide carry?

Answer 15

Acyl groups

Question 16

What does biotin carry?

Answer 16

CO2

Question 17

What does tetrahydrofolate carry?

Answer 17

1-carbon units

Question 18

What does S-adenosylmethionine carry?

Answer 18

methyl groups

Question 19

What does TPP carry?

Answer 19

Aldehydes

Question 20

NADPH is used in what four things

Answer 20

1) anabolic processes
2) respiratory burst
3) cytochrome p-450 system
4) glutathione reductase

Question 21

NAD+ is usually used in catabolic or anabolic processes?

Answer 21

Catabolic

Question 22

Is it glucokinase or hexokinase in the liver?

Answer 22

Glucokinase

Question 23

What has a lower Km – glucokinase or hexokinase?

Answer 23

hexokinase

Question 24

What has a lower Vmax – glucokinase or hexokinase?

Answer 24

hexokinase

Question 25

True or false: hexokinase is induced by insulin?

Answer 25

False. Glucokinase is though

Question 26

True or false: hexokinase is feedback inhibited by glucose-6-phosphate?

Answer 26

True. Glucokinase is not, however

Question 27

How many NADH are produced from glycolysis?

Answer 27

two

Question 28

Enzymes in glycolysis which require ATP input (2)

Answer 28

1) Hexokinase/glucokinase | 2) phosphofructokinase-1

Question 29

Enzymes in glycolysis which produce ATP (2)

Answer 29

1) phosphoglycerate kinase | 2) pyruvate kinase

Question 30

Regulator of hexokinase

Answer 30

Glucose-6-phosphate (negative)

Question 31

Regulator of glucokinase

Answer 31

Fructose-6-phosphate (negative)

Question 32

Regulators of phosphofructokinase-1 (4)

Answer 32

1) AMP (pos) 2) fructose-2,6-bisphosphate (pos) 3) ATP (neg) 4) citrate (neg)

Question 33

Regulators of pyruvate kinase (3)

Answer 33

1) fructose-1,6-bisphosphate (pos) 2) ATP (neg) 3) alanine (neg)

Question 34

What reverses function between fructosebisphosphatase-2 and phosphofructokinase-2 (same enzyme)?

Answer 34

Phosphorylation by protein kinase A

Question 35

Five cofactors necessary for pyruvate dehydrogenase's function

Answer 35

1) Thiamine pyrophosphate 2) lipoic acid 3) CoA 4) FAD 5) NAD+

Question 36

Causes a buildup of pyruvate that gets shunted to lactate and alanine. X-linked condition

Answer 36

Pyruvate dehydrogenase complex deficiency

Question 37

Four destinations of pyruvate

Answer 37

1) alanine 2) oxaloacetate 3) TCA cycle 4) lactate

Question 38

FADH2 produced by the TCA Cycle

Answer 38

1

Question 39

NADH produced by the TCA cycle

Answer 39

3

Question 40

CO2 produced by the TCA cycle

Answer 40

2

Question 41

Five cofactors necessary for alpha-ketoglutarate's function

Answer 41

1) Thiamine pyrophosphate 2) lipoic acid 3) CoA 4) FAD 5) NAD+

Question 42

Four irreversible enzymes of gluconeogenesis

Answer 42

1) pyruvate carboxylase 2) Phosphoenolpyruvate carboxykinase 3) fructose-1,6-biphosphatase 4) glucose-6-phosphatase

Question 43

Where does the pentose phosphate pathway occur in the cell?

Answer 43

cytoplasm

Question 44

What does pyruvate carboxylase require?

Answer 44

biotin and ATP

Question 45

Activator of pyruvate carboxylase

Answer 45

Acetyl-CoA

Question 46

Phosphoenolpyruvate carboxykinase requires ATP or GTP?

Answer 46

GTP

Question 47

Regulators of fructose-1,6-bisphosphatase (3)

Answer 47

1) Citrate (pos) 2) AMP (neg) 3) fructose-2,6-bisphosphate (neg)

Question 48

ATP produced by ATP synthase per NADH

Answer 48

2.5 ATP

Question 49

ATP produced by ATP synthase per FADH2

Answer 49

1.5 ATP

Question 50

Involves a defect in fructokinase. Autosomal recessive. Benign, asymptomatic condition since fructose is not trapped in cells.

Answer 50

Essential fructosuria