Which process is termed as the breakdown of glucose in the absence of oxygen?

The process referred to as the breakdown of glucose in the absence of oxygen is anaerobic glycolysis. This process occurs when oxygen is limited or unavailable, allowing cells to still produce energy by converting glucose into pyruvate through a series of enzymatic reactions. During anaerobic glycolysis, the energy produced is less than what is obtained through aerobic respiration, but it allows for ATP production in situations where oxygen levels are insufficient, such as during intense exercise.

Anaerobic glycolysis results in the conversion of glucose to lactic acid or ethanol and carbon dioxide, depending on the organism. This process is critical for enabling cells to continue generating energy in low-oxygen environments.

In contrast, aerobic respiration requires oxygen and involves more complex pathways, including the citric acid cycle and oxidative phosphorylation, which yield significantly more energy from glucose. Beta oxidation refers specifically to the breakdown of fatty acids for energy, and is unrelated to glucose metabolism. Understanding the distinction between these processes helps clarify why anaerobic glycolysis is specifically identified as the process occurring without oxygen.