What method of energy production occurs when oxygen is present?

Aerobic respiration is the method of energy production that occurs in the presence of oxygen. This process takes place in the mitochondria of cells and is essential for the efficient production of ATP, the primary energy currency of the cell. During aerobic respiration, glucose is broken down with the help of oxygen to produce carbon dioxide, water, and a significant amount of energy (ATP).

The presence of oxygen allows cells to fully oxidize glucose, resulting in more energy being produced compared to anaerobic processes. This efficient conversion is crucial for complex organisms that require large amounts of energy to sustain various bodily functions. In contrast to anaerobic fermentation, which occurs without oxygen and produces less energy, aerobic respiration maximizes the energy yield from nutrients.

Although cellular respiration encompasses both aerobic and anaerobic processes, the specified focus here on oxygen presence clearly identifies aerobic respiration as the correct method.