Name one substance that is produced in anaerobic respiration by an organism but not in aerobic respiration.

Ethanol is produced as the result of the breakdown of pyruvate during anaerobic respiration, not in aerobic respiration. Fermentation is a form of anaerobic respiration in which alcohol is formed by the breakdown of glucose in the absence of oxygen. It usually done by the yeast. In alcoholic fermentation, pyruvic acid is converted into ethanol with the liberation of carbon dioxide.