The complete oxidative breakdown of one glucose molecule in the citric acid cycle also known as the Krebs cycle or TCA cycle and oxidative phosphorylation involves several stages: glycolysis, the citric acid cycle, and the electron transport chain/oxidative phosphorylation. The net ATP production per glucose molecule during these processes is as follows:1. Glycolysis: - 4 ATP molecules are produced, but 2 ATP molecules are consumed in the initial steps, resulting in a net gain of 2 ATP molecules.2. Citric Acid Cycle per 1 glucose molecule, remember that 2 pyruvate molecules are produced from 1 glucose molecule :- 1 ATP molecule is produced per turn of the cycle, and since 2 pyruvate molecules are produced from 1 glucose molecule, the citric acid cycle produces a net gain of 2 ATP molecules.3. Electron Transport Chain/Oxidative Phosphorylation:- The NADH and FADH2 molecules produced during glycolysis and the citric acid cycle are used to generate ATP through oxidative phosphorylation. The number of ATP molecules produced depends on the P/O ratio phosphate-to-oxygen ratio , which is the number of ATP molecules produced per pair of electrons donated to the electron transport chain.- In glycolysis, 2 NADH molecules are produced per glucose molecule. Each NADH molecule produces approximately 2.5 ATP molecules in the electron transport chain P/O ratio of 2.5 for NADH . Therefore, 2 NADH x 2.5 ATP/NADH = 5 ATP molecules.- In the citric acid cycle, 6 NADH and 2 FADH2 molecules are produced per glucose molecule. Each NADH molecule produces approximately 2.5 ATP molecules, and each FADH2 molecule produces approximately 1.5 ATP molecules in the electron transport chain P/O ratio of 1.5 for FADH2 . Therefore, 6 NADH x 2.5 ATP/NADH + 2 FADH2 x 1.5 ATP/FADH2 = 15 + 3 = 18 ATP molecules.The net ATP production per glucose molecule during the complete oxidative breakdown in the citric acid cycle and oxidative phosphorylation is the sum of ATP molecules produced in glycolysis, the citric acid cycle, and the electron transport chain/oxidative phosphorylation:2 ATP glycolysis + 2 ATP citric acid cycle + 5 ATP NADH from glycolysis + 18 ATP NADH and FADH2 from citric acid cycle = 27 ATP moleculesHowever, it is important to note that in eukaryotic cells, the 2 NADH molecules produced during glycolysis need to be transported into the mitochondria, which consumes 1 ATP molecule per NADH. Therefore, the net ATP production in eukaryotic cells is:27 ATP - 2 ATP transport cost = 25 ATP moleculesSo, the net ATP produced per glucose molecule during the complete oxidative breakdown in the citric acid cycle and oxidative phosphorylation is approximately 25 ATP molecules in eukaryotic cells and 27 ATP molecules in prokaryotic cells.