TCA Flashcards
TCA mnemonic
Caitlyn And Isabel Keep Selling Seashells For Money Officer
Citrate
cis-Aconitate
Isocitrate
α-Ketoglutarate
Succinylcholine-CoA
Succinate
Fumarate
Malate
Oxaloacetate
Which TCA reactions produce CO2?
Isocitrate -> α-ketoglutarate catalyzed by isocitrate dehydrogenase
α-ketoglutarate -> Succinyl-CoA catalyzed by α-ketoglutarate dehydrogenase
Which TCA reactions produce NADH?
Isocitrate -> α-ketoglutarate catalyzed by isocitrate dehydrogenase
α-ketoglutarate -> Succinyl-CoA catalyzed by α-ketoglutarate dehydrogenase
Malate -> Oxaloacetate catalyzed by Malate Dehydrogenase
Which TCA reaction produces FADH2?
Succinate to Fumarate via Succinate Dehydrogenase
Which TCA reaction produces GTP?
Succinyl-CoA to Succinate via Succinylcholine-CoA Synthetase
α-ketoglutarate can be converted to which amino acid?
Glutamate
Isocitrate DH and a-ketoglutarate DH inhibitors
ATP, NADH, succinyl-coA (aKDH)
Isocitrate DH activator
ADP
a-ketoglutarate DH is similar to PDH in what sense?
It uses the same bound cofactors of
TPP
Lipoic acid
FAD
- similar mechanism, but not regulated by phosphorylation/dephosphorylation reactions
How does arsenic poisoning work and which enzymes does it affect?
Arsenite reacts with Lipoid acid
Inhibits:
a-ketoglutarate DH
pyruvate DH
branched chain aa DH
- can also interfere with glycolysis at Glyceraldehyde-3P step
Is the TCA an aerobic or anaerobic pathway?
Aerobic, because O2 is required as the final electron acceptor
TCA overall reaction?
Acetyl-CoA -> 2CO2 + 8H + 8e-
Which enzyme converts Citrate to Isocitrate via cis-Aconitate?
Aconitase, loss of H2O, then gain of H2O
What does Succinyl-CoA synthetase (thiokinase) do?
Cleaves the thioester bond of succinyl-CoA to create Succinate
What are the three irreversible steps of the TCA?
Citrate Synthase
Isocitrate DH
ɑ-ketoglutarate DHC
