although o2 dos not participate directly in tca cycle , the cycle operates only when o2 is present - Biology - Biomolecules

Question

although o2 dos not participate directly in tca cycle , the cycle
operates only when o2 is present ? why?

Mushtaq · Accepted Answer

Hi Arun,
Please find below the solution to the asked query:
Tricarboxylic acid Cycle (TCA) or citric acid cycle results in
the complete oxidation of pyruvic acid to yield three molecules of
CO2 During this cycle, the NAD+ is reduced to
NADH at three places to release CO2 and FADH at one
place into FADH2 Thus, NAD+ is necessary for
the decarboxylation reaction (removal of CO2) in TCA
cycle This NAD+ is needed to be regenerated by oxidation
of NADH to keep cycle going For the regeneration of NAD+, the
oxygen is needed The oxygen is necessary for the electron transport
chain to function that recycles NADH back to NAD+ and
FADH2 to back to FADH Hence, oxygen is not involved
directly in TCA but is required for continuous regeneration of
NAD+ and FADH, so that pyruvate can be oxidised
completely

Hope this information will clear your doubts about the role of
O2 in TCA cycle
If you have any more doubts just ask here on the forum and our
experts will try to help you out as soon as possible

Regards

although o2 dos not participate directly in tca cycle , the cycle operates only when o2 is present ? why?