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Flashcards in TCA cycle Deck (27)
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0
Q

Vitamin precursor of CoA

A

Pantothenate

Niacin is for NAD
riboflavin is for FAD and FMN

1
Q

what can generate Acetyl CoA?

A
pyruvate 
acetate 
ketone bodies 
fatty acids 
amino acids
2
Q

Lack of NADH activates flux through which enzymes?

A

Isocitrate dehydrogenase
a-ketoglutarate dehydrogenase
malate dehydrogenase

3
Q

which enzymes in TCA have Fe-S centers?

A

Succinate dehydrogenase

aconitase

4
Q

What enzymes in TCA contain bound FAD

A

succinate dehydrogenase

a-ketoglutarate dehydrogenase

5
Q

water soluble protein found in intermembrane space

A

cytochrome c

6
Q

what generates the proton motive force?

A

there is an electrical component and an pH driven component

7
Q

Acetyl CoA and OAA and water =

A

citrate

via citrate synthase

8
Q

citrate =

A

isocitrate via Aconitase

reversible

9
Q

isocitrate + NAD+ =

A

a-ketoglutarate + NADH + H+ + CO2

via isocitrate dehydrogenase

10
Q

a-ketoglutarate + CoASH +NAD+ =

A

Succinyl CoA + NADH + H+ CO2

via a-ketoglutarate dehydrogenase complex

11
Q

Succinyl CoA + GDP + Pi =

A

Succinate + GTP + CoASH

via succinyl CoA synthetase

12
Q

Succinate + [FAD] =

A

fumarate + [FADH2]

via succinate dehydrogenase

13
Q

Fumarate + h2O =

A

L-malate

via fumarase

14
Q

L-malate + NAD+ =

A

OAA + NADH + H+

via malate dehydrogenase

15
Q

net reaction for TCA

Acetyl CoA + 3 NAD+ + [FAD] + GDP + Pi + H2O =

A

CoASH + 3 NADH + [FADH2] + GTP + 2 CO2 + 3 H+

16
Q

Simple combustion of acetate

A

acetate + 2 O2 + H+ = 2 CO2 + 2 H2o

17
Q

Anapleurotic reaction of Acetyl CoA

A

fatty acids

18
Q

Anapleurotic rxn of a-ketoglutarate

A

Glutamate which could be used to make purines

19
Q

anapleurotic rxn of Succinyl CoA

A

can be used to make d-aminolevulinate which can be used to porphyrins

20
Q

Fumarate and OAA in an anapleurotic rxn can produce

A

aspartate which can be used to make pyrimidines

21
Q

Arsenic poisoning

A

inhibits dehydrogenases (pyruvate DH and succinate DH) and Complex IV
affects DH in glycolysis and gluconeogenic pathways
so inhibits both aerobic and anaerobic pathways

22
Q

how is a-ketoglutarate dehydrogenase complex regulated?

A

AMP activates
NADH inhibits
Succinyl CoA inhibits

23
Q

How is isocitrate dehydrogenase regulated?

A

Inhibited by ATP and NADH

upregulated by ADP

24
Q

how is citrate synthase regulated?

A

Inhibited by ATP, NADH and Succinyl CoA

25
Q

how is pyruvate dehydrogenase regulated?

A

Inhibited by ATP, Acetyl CoA, NADH

upregulated by NAD+ and CoA

26
Q

how is pyruvate carboxylase regulated?

A

upregulated by Acetyl CoA