What is the process called in which pyruvic acid is broken down in the absence of oxygen?

The process in which pyruvic acid is broken down in the absence of oxygen is known as fermentation. This biological process allows cells to generate energy when oxygen is limited or absent by converting pyruvate, the end product of glycolysis, into various byproducts, such as lactic acid or ethanol.

In fermentation, the energy from the breakdown of pyruvate is harvested in a way that does not require oxygen, allowing organisms that perform fermentation to survive in anaerobic conditions. This is crucial for many microorganisms and some muscle cells in higher organisms when oxygen supply is low.

Glycolysis, while a crucial step that produces pyruvic acid, occurs regardless of the presence of oxygen and does not involve the breakdown of pyruvate itself. Aerobic respiration is the process that utilizes oxygen to break down pyruvate and is thus distinct from fermentation. Oxidation is a broader term describing any reaction in which electrons are transferred, which does not specifically refer to the breaking down of pyruvate in the absence of oxygen.