Citric Acid Cycle

Question 1

What is the enzyme used in reaction 1

Answer 1

Citrate Synthase

Question 2

What is the enzyme used in reaction 2

Answer 2

aconitase

Question 3

What is the enzyme used in reaction 3

Answer 3

isocitrate dehydrogenase

Question 4

What is the enzyme used in reaction 4

Answer 4

alpha-ketoglutarate dehydrogenase complex

Question 5

What is the enzyme used in reaction 5

Answer 5

succinyl-CoA synthetase

Question 6

What is the enzyme used in reaction 6

Answer 6

Succinate dehydrogenase

Question 7

What is the enzyme used in reaction 7

Answer 7

fumarase

Question 8

What is the enzyme used in reaction 8

Answer 8

L-Malate dehydrogenase

Question 9

Reactants in reaction 1

Answer 9

Acetyl CoA + Oxaloacetate + H2O

Question 10

Reactants in reaction 2

Answer 10

Citrate

Question 11

Reactants in reaction 3

Answer 11

isocitrate + NAD + H+

Question 12

Reactants in reaction 4

Answer 12

alpha-ketoglutarate + CoASH + NAD+

Question 13

Reactants in reaction 5

Answer 13

succinyl - CoA + GDP + Pi

Question 14

Reactants in reaction 6

Answer 14

succinate + FAD

Question 15

Reactants in reaction 7

Answer 15

fumarate + H2O

Question 16

Reactants in reaction 8

Answer 16

L-Malate + NAD

Question 17

Products in reaction 1

Answer 17

Citrate + CoASH

Question 18

Products in reaction 2

Answer 18

isocitrate (intermediate is cis-aconitate) + H2O goes out and then back in

Question 19

Products in reaction 3

Answer 19

alpha-ketoglutarate (intermediate oxalosuccinate) + NADH H+ + CO2

Question 20

Products in reaction 4

Answer 20

succinly-CoA + NADH + CO2

Question 21

Products in reaction 5

Answer 21

succinate + GTP + CoASH

Question 22

Products in reaction 6

Answer 22

fumarate + FADH2

Question 23

Products in reaction 7

Answer 23

L-malate

Question 24

Products in reaction 8

Answer 24

oxaloacetate + NADH + H+

Question 25

Which reactions are irreversible

Answer 25

1,3,4

Question 26

Krebbs overall Reactants

Answer 26

Acetyl CoA + 3NAD + 1FAD + GDP + Pi + 2H2O

Question 27

Krebbs overall products

Answer 27

2Co2 + 3NADH + FADH2 + GTP + CoAsh

Question 28

Which enzymes regulate the krebs cycle

Answer 28

1. Isocitrate dehydrogenase
2. alpha - keto-glutamate dehydrogenase complex
3. Citrate synthase (bacteria only)

Question 29

What regulates isocitrate dehydrogenase

Answer 29

1. NADH & ATP –> inhibit
2. ADP –> activated allosterically

Question 30

what regulates alpha - keto-glutamate dehydrogenase complex

Answer 30

NADH, ATP, succinyl CoA (all inhibit)

Question 31

What regulates citrate synthase

Answer 31

ATP (inhibits)

Question 32

what type of reaction is reaction 1

Answer 32

a) aldol condensation (forms citryl CoA)
b) hydrolysis (forms citrate and coASH)
Overall: condensation

Question 33

what type of reaction is reaction 2

Answer 33

a) dehydration (form cis-aconitase)
b) hydration (generates isocitrate)
overall: isomerization

Question 34

what type of reaction is reaction 3

Answer 34

a) oxidation (forms oxalosuccinate –> NAD reduced to NADH)
b) decarboxylation
overall: oxidative decarboxylation

Question 35

what type of reaction is reaction 4

Answer 35

oxidative decarboxylation

Question 36

what type of reaction is reaction 5

Answer 36

substrate level phosphorylation & acyl transfer

Question 37

what type of reaction is reaction 6

Answer 37

oxidation

Question 38

what type of reaction is reaction 7

Answer 38

hydration

Question 39

what type of reaction is reaction 8

Answer 39

oxidation

Question 40

when a reaction is oxidized, what happens to NAD

Answer 40

it is reduced to NADH (and vice versa)

Question 41

what converts GTP to ATP

Answer 41

nucleoside diphosphate kinase