Bioenergetics and TCA cycle Flashcards Preview

IUSM Biochemistry > Bioenergetics and TCA cycle > Flashcards

Flashcards in Bioenergetics and TCA cycle Deck (19)
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1
Q

What is an example of a biologically common coupled reaction?

A

ADP to ATP

2
Q

What vitamin does thiamine come from?

A

Vitamin B1

3
Q

Pyruvate dehydrogenase complex has a very similar structure to what TCA cycle enzyme?

A

alpha-ketoglutarate dehydrogenase

4
Q

What three cofactors do a-keto dehydrogenase and PDC require?

A

Thiamine pyrophosphate
lipoic acid (lipoamide)
FAD

5
Q

What complex of PDC/a-keto dehydro is thiamine the cofactor for?

A

E1

6
Q

What complex of PDC/a-keto dehydro is lipoic acid (lipoamide) the cofactor for?

A

E2

7
Q

What complex of PDC/a-keto dehydro is FAD (lipoamide) the cofactor for?

A

E3

8
Q

What is an irreversible inhibitor of dihydrolipoamide in PDC complex E3?

A

Arsenite (10x more toxic) and arsentate

9
Q

High citrate concentrations indicates the presence of a lot of acetyl CoA, which stimulates the formation of what?

A

Fatty acids

10
Q

What is dry beriberi?

A

Low thiamine (B1) + peripheral neuropathy + impaired reflex functions

11
Q

What is wet beriberi?

A

Low thiamine (B1) + cardiovascular disease

12
Q

Alcohol abuse inhibits the uptake of what?

A

thiamine

13
Q

Can acetyl-CoA cross back into the cytoplasm?

A

No, it must first be changed to citrate

14
Q

What does pyruvate carboxylase do?

A

Uses ATP to generate oxaloacetate from pyruvate to keep the TCA cycle running.

15
Q

What happens in the TCA cycle when there is too much Acetyl CoA?

A

It is exported as citrate

16
Q

What are pathways or reactions that replenish the TCA cycle intermediates?

A

Anaplerotic Pathways

17
Q

How much ATP is each NADH worth for the ETC?

A

2.5 ATP

18
Q

How much ATP is each FADH2 worth for the ETC?

A

1.5 ATP

19
Q

How much ATP potential do you get from the TCA cycle including the GTP generated?

A

10 potential ATP