Oxidative Phosphorylation

Coenzyme Oxidation and Redox Potentials:

NADH(reductant) + H+ + 1/2O2(oxidant) → NAD+ + H2O

  • Oxidation

    • NAD+ + 2H+ + 2e- → NADH + H+, E0 = -0.32V.

  • Reduction

    • 1/2O2 + 2H+ + 2e- → H2O, E0 = 0.816V

ΔE0 = E0(reduction/acceptor) - E0(oxidation/donor)

  • ΔE0 = 0.816 -(-0.32) = 1.136V.

The nernst equation shows that ΔG0 = -nFE0.

  • ΔG0 = -(2) x (96.485kJ/Vmol) = -219.21kJ/mol

A reaction with a net positive ΔE0 yields a negative ΔG0 which results in a spontaneous exergonic reaction.