TCA Cycle Flashcards
All TCA Cycle enzymes are in the mitochondrial matrix except _____ which is located in the inner mitochondrial membrane.
succinate dehydrogenase
The condensation of acetyl-CoA and oxaloacetate produces ______ using the enzyme _____
citrate; citrate synthase
This enzyme isomerizes citrate to Isocitrate. This enzyme is also inhibited in Fluoroacetate poisoning
aconitase
This is the key regulatory enzyme in TCA Cycle. It oxidizes isocitrate to a-ketoglutarate
isocitrate dehydrogenase
The five cofactors of the enzyme a-ketoglutarate dehydrogenase which helps in converting a-ketoglutarate to succinyl CoA
TPP, Lipoic acid, CoASH, FAD, NAD
Cleaving the high energy thioester bond in this compound produces GTP.
Succinyl CoA (to Succinate); succinyl-CoA synthase
After this step in TCA cycle, 6 of the 8 electrons from the carbons of acetyl CoA are captured
Succinate –> Fumarate produces FADH2
The oxidation of ____ leads the production of oxaloacetate
malate via malate dehydrogenase
Coenzymes used in converting pyruvate to acety CoA
Thiamine pyrophosphate
Lipoic acid
Coenzyme A
FAD
NAD
What is the role of your citric acid cycle?
- Formation of ATP
2. Substrates for gluconeognesis, aminoacid synthesis, and fatty acid synthesis
What step of ETC does not happen in the mitochondrial matrix?
succinate dehydrogenase
it happens in the inner mitochondrial membrane
What are the products of 1 cycle of TCA?
- 2CO2
- 1 GTP
- 3 NADH
- 1 FADH2
What is the rate limiting step of citric acid cycle
Isocitrate to alpha-ketoglutarate
isocitrate dehydrogenase
What are the co-enzymes needed by the alpha ketoglutarate in converting alpha ketoglutarate to succinyl-CoA?
- Thiamin pyrophosphate
- Lipoic acid
- Coenzyme A
- FAD
- NAD
What inhibits the enzyme aconitase?
Fluoroacetate
[Steps of the TCA cycle: what enzyme is used]
- Citrate to Isocitrate
Aconitase
Inhibited by Flouroacetate
[Steps of the TCA cycle: what enzyme is used]
- Acetyl CoA + Oxaloacetate to Citrate
Citrate Synthase
[Steps of the TCA cycle: what enzyme is used]
- Isocitrate to alpha ketoglutarate
Isocitrate dehydrogenase
[Steps of the TCA cycle: what enzyme is used]
- alpha ketoglutarate to succinyl CoA
alpha ketoglutarate dehydrogenase
Inhbited by: Arsenite and ammonia
[Steps of the TCA cycle: what enzyme is used]
- Succinyl CoA to Succinate
Succinate thiokinase/Succinyl CoA synthetase
Produce GTP
[Steps of the TCA cycle: what enzyme is used]
- Scuccinate to fumarate
Succinate dehydrogenase
Produce: FADH2
[Steps of the TCA cycle: what enzyme is used]
- Fumarate to malate
fumarase or fumarate hydratase
[Steps of the TCA cycle: what enzyme is used]
- Malate to oxaloacetate
malate dehydrogenase
Produces NADH
TCA intermediate that delivers acetyl CoA to cytosol for FA synthesis
Citrate
