End product of anaerobic respiration in humans

Options

(a) lactic acid
(b) ethyl alcohol
(c) ethyl alcohol + CO₂
(d) lactic acid + CO₂

Correct Answer:

lactic acid + CO₂

Explanation:

Occasionally in humans, oxygen becomes either unavailable or insufficient, so that oxidative phosphorylation cannot take place. Yet even under these conditions, a small amount of energy can still be released to the cells by the glycolysis stage of carbohydrate degradation, because the chemical reactions for the breakdown of glucose to pyruvic acid do not require oxygen. Under anaerobic conditions, the major portion of the pyruvic acid is converted into lactic acid and CO₂.