Final answer:
The net product of carbohydrate in oxidative phosphorylation when glucose is catabolized is up to 38 ATP, but typically around 36 ATP, due to shuttle systems that transport NADH into the mitochondria. Oxidative phosphorylation generates the bulk of ATP and results in the complete oxidation of glucose to CO2 and H2O.
Step-by-step explanation:
The net product of carbohydrate in oxidative phosphorylation when glucose is the substrate can be summarized as follows:
- Glycolysis yields a net gain of 8 ATP.
- The conversion of 2 pyruvate to 2 acetyl-CoA produces 6 ATP from 2 NADH.
- Two cycles of the citric acid cycle for the 2 acetyl-CoA yield 24 ATP (assuming 12 ATP per cycle).
- The oxidative phosphorylation stage, which includes the electron transport chain and chemiosmosis, generates most of the ATP during glucose catabolism.
The maximum theoretical yield is 38 ATP per molecule of glucose – 34 ATP from oxidative phosphorylation and 4 ATP from substrate-level phosphorylation. However, some ATP may be used during the shuttle of NADH from the cytosol to the mitochondria. The actual ATP yield can vary, with a net gain often totaling around 36 ATP when glycolytic NADH is transported by the glycerol phosphate shuttle. In essence, the complete oxidation of glucose through the processes of glycolysis, the citric acid cycle, and oxidative phosphorylation yields a substantial amount of ATP as the energy currency of the cell, along with the byproducts carbon dioxide and water.