4. Oxidation and phosphorylation of each phosphoglyceraldehye produces 1,3-diphosphoglycerate with a high-energy phosphate bond (wavy orange line) and NADH.
5. Through substrate-level phosphorylation, the high-energy phosphate is removed from the 1,3-diphosphoglycerate and transferred to ADP forming ATP and 3-phosphoglycerate.
6. 3-phosphoglycerate is oxidized to form phosphoenolpyruvate with a high-energy phosphate bond.
7. Through substrate-level phosphorylation, the high-energy phosphate is removed from the phosphoenolpyruvate and transferred to ADP forming ATP and pyruvate.

In summary, one molecule of glucose produces two net ATPs (two ATPs were used at the beginning; four ATPs were produced through substrate-level phosphorylation), two molecules of NADH, and two molecules of pyruvate.

During aerobic respiration, the two pyruvates enter the transition reaction (see Fig. 34C) to produce two NADH, two CO₂, and two molecules of acetyl-CoA. The two acetyl-CoA then enter the Kreb's cycle (see Fig. 35) to be further broken down. During the transition reaction and the Kreb's cycle, the molecules of NADH and FADH₂ produced provide hydrogen ions and electrons to the electron transport system for chemiosmotic phosphorylation (see Fig. 36) and further ATP production.

During fermentation, the pyruvates are converted to some fermentation end product (such as lactate or alcohol and carbon dioxide) without further ATP production.