What is produced by animals during lactic acid fermentation?

Lactic acid fermentation is a biological process that occurs in animal cells, particularly in muscle cells, when oxygen is scarce, such as during intense exercise. In this process, glucose is partially broken down to yield energy. The end products of this fermentation are two molecules of lactic acid and a small amount of energy in the form of two ATP molecules.

When glucose undergoes glycolysis, it is converted into two molecules of pyruvate. In the absence of sufficient oxygen, these pyruvate molecules are then converted into lactic acid. The conversion features the reduction of NAD+ to NADH, which is essential for allowing the continuation of glycolysis, thus enabling a small net gain of ATP. Lactic acid fermentation does not produce ethanol and CO2, which are products of alcoholic fermentation used by yeast and some plants.

Thus, the production of two lactic acids and two ATP molecules encapsulates the essential outcome of lactic acid fermentation in animals, underscoring the crucial mechanism by which cells generate energy under anaerobic conditions.