Chapter 10 - Carb Metabolism II Flashcards
What is the main function of TCA?
Oxidize Acetyl-CoA to H20 and CO2
Produce NADH and FADH2
Review Kiraly notes from Pyruvate dehydrogenase complex
They aren’t Kiralys notes…you wouldn’t want to review those
What are the general methods of forming acetyl-CoA
1) from pyruvate in the pyruvate dehydrogenase complex
2) Fatty acid oxidation (beta)
3) amino acid catabolism
4) ketones
5) alcohol
What is the function of carnitine?
To shuttle the fatty acyl group across the mito membrane
Why are amino acids termed ketogenic?
They can be used to form acutely CoA
- they must lose their amino group and their carbon skeletons can then form ketone bodies
….then to acetyl coa
What is the connection between ketones and acetyl CoA?
Réversible reaction
When PDH is inhibited, AcetylCoA can produce ketones
Name the intermediates of the TCA (8)
Pyruvate -> Acetyl CoA
> Citrate
> Isocitrate
> alpha ketoglutarate
> Succinyl CoA
> Succinate
> Fumarate
> Malate
> Oxaloacetate
Draw out TCA.
Include:
- intermediates
- enzymes
- NADH FADH2 CO2 H2O and GTP
If you don’t use colour, you are a fucking amateur
What is the rate limiting enzyme of the TCA?
Isocitrate dehydrogenase
NAD+ —-> NADH
——>CO2
**first of two carbons in cycle is lost
How much atp do you get from NADH and FADH2
- 5 ATP from NADH
1. 5 ATP form FADH2
Starting from the pyruvate dehydrogenase complex, how many atp are produced?
PDH = 1 NADH = 2.5 TCA = 3 NADH, 1 FADH2, 1GTP = 10
= 12.5 ATP per pyruvate
= 25 ATP per glucose
(If glycolysis included, total around 30-32)
How much ATP is yielded from glycolysis?
2 ATP = 2
2 NADH = 5
What are the control points for the tca?
Include enzymes
Citrate Synthase : atp NADH are allostic inhibitors , as well as citrate
Isocitrate dehydrogenase: (same as above)
Alpha keto glutarate dehydrogenase : succinyl coa and products inhibit
- the complex is stimulated by ADP and Ca2+ ions
Draw out TCA with intermediates and control points
See figure 10.11 (page 349)
Where does the tca take place?
Mito matrix
