TCA Cycle Flashcards
What is the general purpose of the TCA cycle?
Oxidizes the carbons produced in glycolysis to CO2 and harvests the electrons for transport to the respiratory chain for ATP synthesis.
Where does glycolysis occur?
Where does the TCA cycle occur?
Where does OxPhos occur?
Cytoplasm
Cytosol of mitochondria
Inner mitochondrial membrane
How does pyruvate enter the mitochondria?
Carrier that is imbedded between the inner and outer membranes of mitochondria
PDH is activated by Ca2+ signaling. Where might the Ca2+ have come from?
Muscle contraction
Insulin signaling
2 carbons enter the TCA cycle in the form of acetyl-coA. What happens to these carbons?
They are lost as CO2, so there is no net gain of cycle intermediates.
Why is it not possible for glucose synthesis to occur from acetyl coA?
1) The conversion of pyruvate to acetyl coA is irreversible
2) Acetyl coA is completely oxidized in the TCA cycle, so there is no net gain of intermediates and thus no substrates that can be converted to glucose.
What is the TCA cycle an amphibolic pathway?
B/c it acts in both catabolism and anabolism.
What is an anaplerotic reaction?
One that replenishes cycle intermediates
Ex: Pyruvate carboxylate converting pyruvate to oxaloactetate
