Question

If two (2) molecules of pyruvate are oxidized via the PDC and the Citric Acid Cycle in a kidney cell, how many molecules of O2 are utilized?

Answer 1

Upon oxidation of pyruvate to acetyl Co-A, two electrons are released. These electrons are taken by NAD+ and get reduced to NADH. So two pyruvate will give two NADH and two Acetyl Co-A.

Acetyl Co-A upon its oxidation to CO2 produce 3 NADH and 1 FADH. FAD+ takes two-electron gets reduced to FADH.

After complete oxidation of two molecules of pyruvate, we have 8 NADH and two FADH.

NADH and FADH give their electron to electron transport chain and oxidizes to NAD+ and FAD+ respectively.

Electrons are passed through the electron transport chain and ultimately taken by terminal electron acceptor O2 which gets reduced to H2O. The half molecule of O2 is reduced to H2O from two electrons.

So from 8 NADH and two FADH total 10*1/2 = 5 molecules of oxygen are reduced to H2O.

So 5 molecules of O2 are utilized when two molecules of pyruvate are oxidized via the PDC and the Citric Acid Cycle in a kidney cell.

Please write to me if you need more help.