Answer
ATP can be produced both by anerobic reactions and by the aerobic reactions of the Krebs cycle of aerobic cellular reactions.
The reactions of glycolysis and fermentation are anerobic, and do not produce many ATPs per glucose molecule metabolized.
The Krebs cycle reactions require oxygen and produce X15 as many ATPs per glucose molecule metabolized.
Work Step by Step
Glycolysis and anerobic fermentation produce a net of 2 ATPs per glucose molecule metabolized. By contrast, the same glucose molecule passed through the Krebs Cycle will generate a net of 30+ ATPs --dependent on tissue.
