Topic 13 - ETC & Oxidative Phosphorylation

Question 1

After Glycolysis and the TCA Cycle, what happens next and why?

Answer 1

Energy of electron transfer from NADH & FADH2 to Oxygen will drive more ATP synthesis! NAD/NADH and FAD/FADH2 have intermediate reduction potentials that allow them to accept electrons (from catabolic intermediates of Glycolysis and TCA Cycle) and donate them to Oxygen.
Direct transfer of electrons from NADH/FADH2 to Oxygen in a single oxidation/reduction reaction is highly spontaneous but is not an efficient means of harnessing the energy to maximize ATP production.