In prokaryotes:
1. Complete oxidation of one molecule of glucose (glycolysis + citric acid cycle + oxidative phosphorylation) results in the net gain of 38 molecules of ATP.
2. Complete oxidation of one molecule of acetyl Co-A (citric acid cycle + oxidative phosphorylation) results in the net gain of 12 molecules of ATP
ATP Yield From Glucose Oxidation
The process includes glycolysis, Krebs cycle, and the electron transport chain, leading to a total yield of 38 ATP per glucose in prokaryotic cells.
ATP Yield From Acetyl Co-A Oxidation
Each acetyl Co-A molecule entering the Krebs cycle produces:
3 NADH (each ~3 ATP) = 9 ATP
1 FADH2 (each ~2 ATP) = 2 ATP
1 GTP (equivalent to 1 ATP)
Thus, the total yield is 12 ATP per acetyl Co-A.