TCA Flashcards
Are neverending amounts of NAD+ available in a cell?
No (limited)
What does glycolysis do to NAD?
reduces it
How is NAD regenerated?
through pyruvate metabolism
Where are enzymes for TCA?
matrix of mitochondrion
What catalyses the oxidative decarboxylation of pyruvate to acetyl-CoA?
pyruvate dehydrogenase complex (PDC)
How many enzymes does the pyruvate dehydrogenase complex (PDC) consist of?
3 enzymes involved in the actual reaction mechanism
E1, E2 and E3
2 enzymes involved in the control of PDC
(a kinase and a phosphatase in a single polypeptide)
5 coenzymes
thiamine, lipoic acid, coenzyme A, FAD, NAD+
Is oxidative decarboxylation of pyruvate to acetyl-CoA reversible?
No
How many reactions occur in total in TCA?
8
How many oxidation reactions occur?
4
How manny GTP molecules are formed?
1
Which enzyme of TCA is not located in the matrix of the mitrochondrion?
Succinate dehydrogenase (integrated in the inner mitochondrial membrane)
What does each turn of the TCA cycle involve in terms of carbon atoms?
the uptake of two carbon atoms in the form of acetyl-CoA and the release of two carbon atoms as CO2
How many pairs of electrons are transferred from NAD+ to form NADH + H+ per turn of cycle?
3
How many pairs of electrons are used to reduce FAD+ to FADH2 per turn of cycle?
1
Does high ADP and NAD+ mean high or low energy?
low
