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Flashcards in TCA cycle Deck (27)
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what can generate Acetyl CoA?

pyruvate
acetate
ketone bodies
fatty acids
amino acids

1

Vitamin precursor of CoA

Pantothenate

Niacin is for NAD
riboflavin is for FAD and FMN

2

Lack of NADH activates flux through which enzymes?

Isocitrate dehydrogenase
a-ketoglutarate dehydrogenase
malate dehydrogenase

3

which enzymes in TCA have Fe-S centers?

Succinate dehydrogenase
aconitase

4

What enzymes in TCA contain bound FAD

succinate dehydrogenase
a-ketoglutarate dehydrogenase

5

water soluble protein found in intermembrane space

cytochrome c

6

what generates the proton motive force?

there is an electrical component and an pH driven component

7

Acetyl CoA and OAA and water =

citrate
via citrate synthase

8

citrate =

isocitrate via Aconitase

reversible

9

isocitrate + NAD+ =

a-ketoglutarate + NADH + H+ + CO2
via isocitrate dehydrogenase

10

a-ketoglutarate + CoASH +NAD+ =

Succinyl CoA + NADH + H+ CO2
via a-ketoglutarate dehydrogenase complex

11

Succinyl CoA + GDP + Pi =

Succinate + GTP + CoASH
via succinyl CoA synthetase

12

Succinate + [FAD] =

fumarate + [FADH2]
via succinate dehydrogenase

13

Fumarate + h2O =

L-malate
via fumarase

14

L-malate + NAD+ =

OAA + NADH + H+
via malate dehydrogenase

15

net reaction for TCA
Acetyl CoA + 3 NAD+ + [FAD] + GDP + Pi + H2O =

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

16

Simple combustion of acetate

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

17

Anapleurotic reaction of Acetyl CoA

fatty acids

18

Anapleurotic rxn of a-ketoglutarate

Glutamate which could be used to make purines

19

anapleurotic rxn of Succinyl CoA

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

20

Fumarate and OAA in an anapleurotic rxn can produce

aspartate which can be used to make pyrimidines

21

Arsenic poisoning

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

how is a-ketoglutarate dehydrogenase complex regulated?

AMP activates
NADH inhibits
Succinyl CoA inhibits

23

How is isocitrate dehydrogenase regulated?

Inhibited by ATP and NADH
upregulated by ADP

24

how is citrate synthase regulated?

Inhibited by ATP, NADH and Succinyl CoA

25

how is pyruvate dehydrogenase regulated?

Inhibited by ATP, Acetyl CoA, NADH
upregulated by NAD+ and CoA

26

how is pyruvate carboxylase regulated?

upregulated by Acetyl CoA