Flashcards in TCA Cycle Deck (18):
What is the overall output of the TCA cycle?
1 Glucose + 6O2 _6 CO2 + 6H2O + 38 ATP
What transforms pyruvate into Acetyl-CoA?
Pyruvate dehydrogenase complex
What are the parts of pyruvate dehydrogenase complex?
3 enzymes, 5 vitamin B derived cofactors
How is pyruvate dehydrogenase different from _-ketoglutarate dehydrogenase?
PDHC CAN be deactivated via phosphorylation
Acetyl-CoaA + Oxaloacetate _ Citrate + CoASH. Irreversible rxn. 1st source of reducing equivilents
Citrate _ Isocitrate
Isocitrate _ _-ketoglutarate. Rate limiting step of TCA cycle**. Produces NADH and CO2
_-ketogluarate _Succinyl-CoA. Irreversible rxn. Similar structure to PDHC. CANNOT be regulated via phosphorylation. Produces NADH and CO2
Succinyl CoA synthetase/ Succinyl thiokinase
Succinyl-CoA _ Succinate. Only substrate level phosphroylation if the TCA cycle*
Phosphorates ATP from GTP (after succinyl thiokinase step)
Succinate _Fumarate. Produces FADH2
Fumarate _ Malate. Uses H2O
Malate _ Oxaloacetate (NADH)
Malate -Aspartate Shuttle
Replensishes NAD+ in cytosol and NADH in inner mitochondria membrane for electron transport chain
What inhibits citrate synthase?
What inhibits Isocitrate DH?
What stimulates Isocitrate DH?