Chapter 19 Citric acid cycle II

1
Chapter 19 Citric acid cycle -II
2
(No Transcript)
3
The Citric Acid Cycle
4
Regulation of the Citric Acid Cycle
5
(No Transcript)
6
Control of Pyruvate Dehydrogenase
Inhibited by ATP, acetyl CoA and NADH Activated
by ADP
High ATP?kinase activated?
PDH is phosphorylated? inactive
Low ATP? phosphatase activated? phosphate
removed?activated
Acetyl-CoA inhibits. When fats are plentiful
they are burned producing acetyl-CoA and you
dont need any more.
7
Is it possible to synthesize carbohydrates from
acetyl-CoA?
Animals No
8
Plants and some bacteria yes
Glyoxylate pathway
Bypass the 2 CO2 Releasing Sites.
9
The citric acid cycle is also involved in
catabolism.
10
Many biological molecules are synthesized from
intermediates of the citric acid cycle.
11
This may deplete come of the cycle intermediate.
If oxaloacetate is depleted, there is
nothing for acetyl-CoA to bind to and the cycle
stops - unless we replenish oxaloacetate.
How do we do that?
12
Pyruvate CO2 ATP ? oxaloacetate ADP P