Why is anaerobic respiration considered less efficient than aerobic respiration?

Question

a
Less energy is required during anaerobic respiration than aerobic respiration.
b
More ATP molecules are gained in aerobic respiration than in anaerobic respiration.
c
More oxygen is required for anaerobic respiration than for aerobic respiration.
d
Less lactic acid is formed during anaerobic respiration than during aerobic respiratio

Answer 1

The correct answer is:

b More ATP molecules are gained in aerobic respiration than in anaerobic respiration.

Anaerobic respiration generates less ATP because it does not fully oxidize glucose. In aerobic respiration, the presence of oxygen allows for a complete breakdown of glucose to carbon dioxide and water, resulting in a higher yield of ATP (up to about 36-38 ATP molecules per glucose molecule). In contrast, anaerobic respiration typically produces only 2 ATP molecules per glucose molecule through processes like lactic acid fermentation or alcohol fermentation.