Exam 3: Citric Acid Cycle

Question 1

What is an obligate anerobe

Answer 1

only grows in absence of O2, uses fermentation

Question 2

what an aerotolerant anaerobe?

Answer 2

grows in absence of O2, can tolerate some ROSs only uses fermentation

Question 3

Facultative anerobes

Answer 3

can use anaerobic and aerobic metabolism

Question 4

obligate aerobes

Answer 4

need O2, aerobic metabolism, can ferment things but cant survive with that

Question 5

Where does the citric acid cycle happen

Answer 5

in the matrix or space inside the mitochondrial membrane

Question 6

What is the purpose of the CAC

Answer 6

to convert glucose pyruvate into CO2 and produce NADH and FADH2

Question 7

What is NAD

Answer 7

nicatinamide dinucleotide vitamin not produced by body

Question 8

How many electrons do NAD+ and NADH have

Answer 8

NAD+ 10 e-

NADH 12e-

Question 9

What is Delta E not

Answer 9

change in reduction potential

Question 10

What does a small and a large delta E not mean

Answer 10

small: more negative, low affinity for e-
large: more positive, high affinity for e-

Question 11

do reactions in the CAC tend to have larger or smaller delta E not

Answer 11

larger, more negative, higher affinity for e-

Question 12

What is FAD/ FMN

Answer 12

flavin adenine dinucleotide or flavin mononucleotide both made of riboflavin

Question 13

How many electrons do FAD/FMN have and FADH2/FMH2

Answer 13

FAD/FMN: 10e-

FADH2/FMH2: 12e-

Question 14

What is CoASH coenzyme A

Answer 14

non protein organic mol that carries acetyl groups

Question 15

When in the CAC is CoAsh used

Answer 15

acetyl CoA to citrate

Question 16

Where on CoAsh can acetyl group be attached

Answer 16

thioester bond btween 4 phosphopantetheine and 3’ phosphoADP

Question 17

What kind of rxn is the fist rxn in CAC, catalyzed by citrate synthase

Answer 17

condensation rxn

Question 18

What kind of rxn is rxn 2 catalyzed by aconitase

Answer 18

isomerization

Question 19

What kind of rxn is rxn 5 with enzyme succinyl CoA synthase

Answer 19

substrate level phosphorylation

Question 20

What enzyme is highly regulates in CAC and is the only enzyme in mitochondrial membrane

Answer 20

succinate dehydrogenase

Question 21

What kind of rxn is rxn7 with fumerase

Answer 21

hydration, isomerization

Question 22

What are the 3 primary enzymes regulated in CAC

Answer 22

citrate synthase, isocitrate dehydrogenase, alpha ketoglutarate

Question 23

Why is the CAC amphibolic, what else feeds into and out of it

Answer 23

both anabolic and catalytic, can go to gluconeogenesis, can go to AA metabolism both ways (fatty acids and heme) . Can come from pyrimidines and AAs (Asp), or Glu

Question 24

Which enzymes in CAC catalyze oxidative decarboxylation rxns?

Answer 24

isocitrate dehydrogenase and alpha ketogluterate dehydrogenase complex

Question 25

The pyruvate dehydrogenase complex catalyzes the

Answer 25

conversion of pyruvate from glycolysis to acetyl CoA which enters the CAC

Question 26

Which enzyme is the only membrane bound enzyme in the CAC

Answer 26

succinate dehydrogenase

Question 27

which enzyme is not a control point of the CAC

Answer 27

aconitase