Aerobic vs. Anaerobic Metabolism: Which Produces More Energy?

Aerobic metabolism produces far more energy than anaerobic.

• Aerobic: Requires oxygen; complete glucose breakdown via glycolysis, Krebs cycle, electron transport chain → yields 36–38 ATP per glucose.
• Anaerobic: Without oxygen; only glycolysis → yields max 2 ATP per glucose (e.g., fermentation).

Aerobic respiration is vastly more efficient, making it the primary energy pathway when oxygen is available.