Biochem - Metabolism (Basic facts/terminology)

Question 1

What are 4 types of metabolism that occur solely in mitochondria?

Answer 1

(1) Fatty acid oxidation (Beta-oxidation) (2) Acetyl-CoA production (3) TCA Cycle (4) Oxidative phosphorylation

Question 2

What are 6 types of metabolism that occur solely in cytoplasm?

Answer 2

(1) Glycolysis (2) Fatty acid synthesis (3) HMP shunt (4) Protein synthesis (RER) (5) Steroid synthesis (SER) (6) Cholesterol synthesis

Question 3

What are the major options for sites of metabolism?

Answer 3

Metabolism sites: (1) Mitochondria (2) Cytoplasm (3) Both

Question 4

What are 3 types of metabolism that occur in both the mitochondria and cytoplasm?

Answer 4

(1) Heme synthesis (2) Urea cycle (3) Gluconeogenesis; Think: “HUGs take two (i.e., both)”

Question 5

What is the function of glucokinase?

Answer 5

Glucokinase is an enzyme that catalyzes the phosphorylation of glucose using a molecule of ATP

Question 6

What is the function of a Kinase? Give an example.

Answer 6

Uses ATP to add high-energy phosphate group onto substrate (e.g., phosphofructokinase)

Question 7

What is the function of a Phosphorylase? Give an example.

Answer 7

Adds inorganic phosphate onto substrate without using ATP (e.g., glycogen phosphorylase)

Question 8

What is the function of a Phosphatase? Give an example.

Answer 8

Removes phosphate group from substrate (e.g., fructose-1,6-biphosphatase).

Question 9

What is the function of a Dehydrogenase? Give an example.

Answer 9

Catalyzes oxidation-reduction reactions (e.g., pyruvate dehydrogenase).

Question 10

What is the function of a Hydroxylase? Give an example.

Answer 10

Adds hydroxyl group (-OH) onto substrate (e.g., tyrosine hydroxylase).

Question 11

What is the function of a Carboxylase? Give an example.

Answer 11

Transfers CO2 groups with the help of biotin (e.g., pyruvate carboxylase).

Question 12

What is the function of a Mutase? Give an example.

Answer 12

Relocates a functional group within a molecule (e.g., vitamin B12-dependent methylmalonyl-CoA mutase).

Question 13

What is the rate-determining enzyme of Glycolysis?

Answer 13

Phosphofructokinase-1 (PFK-1)

Question 14

For which process is Phosphofructokinase-1 (PFK-1) the rate-determining enzyme? What are the positive versus negative regulators of PFK-1?

Answer 14

Glycolysis; POSITIVE: AMP, Fructose-2,6-bisphosphate; NEGATIVE: ATP, citrate

Question 15

What is the rate-determining enzyme of Gluconeogenesis?

Answer 15

Fructose-1,6-bisphosphatase

Question 16

For which process is Fructose-1,6-bisphosphatase the rate-determining enzyme? What are the positive versus negative regulators of Fructose-1,6-biphosphate?

Answer 16

Gluconeogenesis; POSITIVE: ATP, acetyl-CoA; NEGATIVE: AMP, fructose-2,6-bisphosphate

Question 17

What is the rate-determining enzyme of the TCA cycle?

Answer 17

Isocitrate dehydrogenase

Question 18

For which process is Isocitrate dehydrogenase the rate-determining enzyme? What are the positive versus negative regulators of Isocitrate dehydrogenase?

Answer 18

TCA cycle; POSITIVE: ADP; NEGATIVE: ATP, NADH

Question 19

What is the rate-determining enzyme of Glycogenesis?

Answer 19

Glycogen synthase

Question 20

For which process is Glycogen synthase the rate-determining enzyme? What are its positive versus negative regulators?

Answer 20

Glycogenesis; POSITIVE: Glucose-6-phosphate, Insulin, Cortisol; NEGATIVE: Epinephrine, glucagon

Question 21

What is the rate-determining enzyme of Glycogenolysis?

Answer 21

Glycogen phosphorylase

Question 22

For which process is Glycogen phosphorylase the rate-determining enzyme? What are its positive versus negative regulators?

Answer 22

Glycogenolysis; POSITIVE: Epinephrine, Glucagon, AMP; NEGATIVE: Glucose-6-phosphate, Insulin, ATP

Question 23

What is the rate-determining enzyme of the HMP shunt?

Answer 23

Glucose-6-phosphate dehydrogenase (G6PD)

Question 24

For which process is Glucose-6-phosphate dehydrogenase the rate-determining enzyme? What are its positive versus negative regulators?

Answer 24

HMP shunt; POSITIVE: NADP+; NEGATIVE: NADPH

Question 25

What is the rate-determining enzyme of De novo pyrimidine synthesis?

Answer 25

Carbamoyl phosphate synthetase II

Question 26

For which process is Carbamoyl phosphate synthetase II the rate-determining enzyme?

Answer 26

De novo pyrimidine synthesis

Question 27

What is the rate-determining enzyme of De novo purine synthesis?

Answer 27

Glutamine-Phosphoribosylpyrophosphate (PRPP) amidotransferase

Question 28

For which process is Glutamine-Phosphoribosylpyrophosphate (PRPP) amidotransferase the rate-determining enzyme? What are its negative regulators?

Answer 28

De novo purine synthesis; NEGATIVE: AMP, Inosine monophosphate (IMP), GMP

Question 29

What is the rate-determining enzyme of the Urea cycle?

Answer 29

Carbamoyl phosphate synthetase I

Question 30

For which process is Carbamoyl phosphate synthetase I the rate-determining enzyme? What is its positive regulator?

Answer 30

Urea cycle; POSITIVE: N-acetylglutamate

Question 31

What is the rate-determining enzyme of Fatty acid synthesis?

Answer 31

Acetyl-CoA carboxylase (ACC)

Question 32

For which process is Acetyl-CoA carboxylase (ACC) the rate-determining enzyme? What are its positive versus negative regulators?

Answer 32

Fatty acid synthesis; POSITIVE: Insulin, citrate; NEGATIVE: Glucagon, Palmitoyl-CoA

Question 33

What is the rate-determining enzyme of Fatty acid oxidation?

Answer 33

Carnitine acyltransferase I

Question 34

For which process is Carnitine acyltransferase I the rate-determining enzyme? What is its negative regulator?

Answer 34

Fatty acid oxidation; NEGATIVE: Malonyl-CoA

Question 35

What is the rate-determining enzyme of Ketogenesis?

Answer 35

HMG-CoA synthetase

Question 36

For which process is HMG-CoA synthetase the rate-determining enzyme?

Answer 36

Ketogenesis

Question 37

What is the rate-determining enzyme of Cholesterol synthesis?

Answer 37

HMG-CoA reductase

Question 38

For which process is HMG-CoA reductase the rate-determining enzyme? What are its positive versus negative regulators?

Answer 38

Cholesterol synthesis; POSITIVE: Insulin, Thyroxine; NEGATIVE: Glucagon, Cholesterol