Which process converts pyruvate into lactate in anaerobic conditions?

Lactic acid fermentation is the process that converts pyruvate into lactate when oxygen is not available, which is characteristic of anaerobic conditions. During this process, the pyruvate produced from glycolysis is reduced by NADH to form lactate, regenerating NAD+ in the process. This is crucial because it allows glycolysis to continue under anaerobic conditions by ensuring a constant supply of NAD+, enabling continued ATP production in the absence of oxygen.

This mechanism is employed by certain microorganisms and is also a pathway used by animal cells, such as muscle cells, during strenuous activity when oxygen supply is limited. The accumulation of lactate can cause muscle fatigue, but it also serves as a temporary solution to energy needs when aerobic respiration cannot occur.

In contrast, aerobic respiration utilizes oxygen to fully oxidize glucose into carbon dioxide and water, while alcohol fermentation converts pyruvate into ethanol and carbon dioxide, typically in yeast cells. Oxidative respiration involves electron transport processes and is part of aerobic respiration, relying on oxygen for energy production.