What is the net gain of ATP molecules synthesized directly through substrate-level phosphorylation during the complete aerobic respiration of one molecule of glucose?

Step-by-step solution

During the complete aerobic respiration of one molecule of glucose, substrate-level phosphorylation occurs in two main stages: In glycolysis, 4 ATP molecules are produced directly, but 2 ATP molecules are consumed in the preparatory phase. Thus, the net gain of ATP from substrate-level phosphorylation in glycolysis is 2 ATP. In the Krebs cycle, 1 molecule of GTP (which is equivalent to ATP) is produced per turn during the conversion of succinyl-CoA to succinic acid. Since one glucose molecule yields two molecules o