Yield of ATP
At this point the yield of ATP is 4 moles per mole of Glucose as it passes through the Krebs cycle.
This is not much more than the 2 moles which would have been produced from glycolysis.
However, NADH and FADH2 are energy rich molecules
Their oxidation is highly exergonic and is coupled with the production of ATP from ADP
Oxidation of 1 mole NADH produces 3 moles ATP
Oxidation of 1 mole FADH2 produces 2 moles ATP
Thus total ATP yield = (10 × 3) + (2 × 2) + 4 = 38 moles ATP per mole Glucose