fermentation

Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. Fermentation is important in anaerobic conditions when there is no oxidative phosphorylation to maintain the production of ATP by glycolysis. During fermentation, pyruvate is metabolised to various compounds.

Homolactic fermentation is the production of lactic acid from pyruvate; alcoholic fermentation is the conversion of pyruvate into ethanol and carbon dioxide; and heterolactic fermentation is the production of lactic acid as well as other acids and alcohols.