Which process allows cells to release energy without oxygen?

Fermentation is the process that enables cells to produce energy in the absence of oxygen. During fermentation, glucose is partially broken down to release energy, resulting in end products such as lactic acid or ethanol, depending on the type of organism and the specific conditions. This anaerobic process is crucial for cells, particularly in environments where oxygen is scarce, allowing them to continue generating ATP, the energy currency of the cell.

In contrast, aerobic respiration requires oxygen to effectively generate energy through a more efficient metabolic pathway, while cellular respiration encompasses both aerobic and anaerobic processes. Photosynthesis, on the other hand, is primarily a process used by plants to convert light energy into chemical energy, not related to energy release in the absence of oxygen.