Which process converts glucose to pyruvate without oxygen use?

The process that converts glucose to pyruvate without the use of oxygen is glycolysis. Glycolysis is a fundamental metabolic pathway that occurs in the cytoplasm of cells and involves a series of enzymatic reactions that break down glucose, a six-carbon sugar, into two molecules of pyruvate, which contain three carbons each.

This process consists of ten steps and does not require oxygen, making it an anaerobic pathway. It serves as the first stage of cellular respiration, even though it can occur in both oxygen-rich and oxygen-poor environments. Through glycolysis, a net gain of two molecules of ATP (the energy currency of the cell) and two molecules of NADH (which can be utilized in further energy-generating processes) are produced from one molecule of glucose.

While glycolysis is often followed by further processes, such as fermentation in anaerobic conditions or the Krebs cycle in aerobic conditions, the transformation of glucose to pyruvate itself is solely a result of glycolysis. Other options, like glycogenesis, fermentative processes, and cellular respiration, involve either different metabolic processes or, in the case of cellular respiration, a reliance on oxygen after glycolysis.