Anaerobic respiration yields much less energy than aerobic respiration.
The main reasons are:
(i) There is incomplete breakdown of respiratory substrate.
(ii) One of the end product of anaerobic respiration is organic that still contains energy.
(iii) NADH2 produced during glycolysis is often reutilized.
(iv) Regeneration of NAD+ from NADH2 does not produce ATP.
(v) Electron transport chain is absent.
(vi) Oxygen is not used for accepting electrons and protons.
