In a eukaryotic cell relying on aerobic metabolism, which process regenerates the largest share of ATP from ADP and inorganic phosphate?

Core Concept

Glycolysis and the Krebs cycle contribute only a few ATP apiece through substrate-level phosphorylation. The bulk of the harvest, roughly 26 to 28 ATP per glucose, arises when NADH and FADH2 donate electrons to the respiratory chain. Proton pumping stores that energy as an electrochemical gradient, and ATP synthase converts it back into usable currency. This is why mitochondria dominate the ATP economy of active cells.