biochem 2 krebs cycle

Question 1

What enzyme catalyses pyruvate to acetyl CoA?

Answer 1

PDC—–pyruvate dehydrogenase

Question 2

what is the first subsrate in krebs cycle?

Answer 2

Acetyl CoA

Question 3

What is the first reaction of kreb’s cycle?

Answer 3

condensation of Acetyl CoA by enzyme citrate synthase to create citrate by the addition of water and the byproduct CoASH

Question 4

What is the second reaction of Kreb’s cycle?

Answer 4

the movement of hydroxyl group on Carbon 2 of citrate to carbon 3 of Isocitrate catalyzed by aconitase

Question 5

What is the third reaction of Kreb’s cycle?

Answer 5

the oxidation and decarboxylation of isocitrate to give

1. NADH + (H+) & CO2
2. Alpha-ketoglutarate

Question 6

What is the catalyst of the third reaction?

Answer 6

isocitrate dehydrogenase

Question 7

What is the fourth reaction of Kreb’s cycle?

Answer 7

The oxidation and decarboxylation of alpha-ketogluarate to produce
1. NADH + (H+) & CO2
with the addition of CoASH
2.Succinyl CoA

Question 8

What is the catalyst of the fourth reaction?

Answer 8

alpha-ketoglutarate dehydrogenase

Question 9

What forms at the ketone end of Succinyl CoA after the fourth reaction?

Answer 9

a high energy bond

Question 10

What is the fifth reaction of Kreb’s cycle?

Answer 10

substrate level phosphorylation of Succinyl CoA (no O2 needed) to produce
1. CoASH
with the addition of GDP + P
2. GTP
3. Succinate

Question 11

What is the catalyst used for the fifth reaction?

Answer 11

succinate thiokinase

Question 12

What is the sixth reaction of Kreb’s cycle?

Answer 12

oxidation of Succinate to produce (after the addition of FAD

1. FADH (2H)
2. Fumarate

Question 13

What is the sixth reaction’s catalyst?

Answer 13

succinate dehydrogenase

Question 14

What is the seventh reaction of Kreb’s cycle?

Answer 14

hydration of fumarate to produce (after the addition of H2O) hydration duh!
1. Malate by the calalyst fumarase

Question 15

What is the eighth and final reaction of Kreb’s cycle?

Answer 15

oxidation of Malate to produce (after the addition of NAD+

1. NADH + (H+)
2. Oxaloacetate

Question 16

What is the catalyst of the eighth reaction?

Answer 16

malate dehydrogenase

Question 17

What are the reaction steps that produce NADH + H+ or FADH (2H)

Answer 17

reaction

3. NADH + (H+)
4. NADH +(H+)
5. FADH (2H)
6. NADH +(H+)

Question 18

What reaction (s) produce GTP?

Answer 18

reaction 5

Question 19

What reactions produce CO2?

Answer 19

reaction 3 & 4

Question 20

increased lactate produces _____

Answer 20

acidosis

Question 21

Where is the 3 NADH and 1 FADH being sent?

Answer 21

ETC electron transport chain for oxidative phosphorylation

Question 22

What are the first 4 substates used in Kreb’s cycle?

Answer 22

1. Acetyl CoA
2. Citrate
3. Isocitrate
4. alpha-ketoglutarate

Question 23

What are the first four catalysts used in Kreb’s cycle?

Answer 23

1. citrate synthase
2. aconitase
3. isocitrate dehydrogenase
4. alpha-ketoglutarate dehydrogenase

Question 24

What are the last 5 substrates used in Kreb’s cycle?

Answer 24

5. Succinyl CoA
6. Succinate
7. Fumarate
8. Malate
9. Oxaloacetate

Question 25

What are the last 4. catalysts used in Kreb's cycle?

Answer 25

5. succinate thiokinase 6. succinate dehydrogenase 7. fumarase 8. malate dehydrogenase