What chemical change does oxygen undergo to support life?

Oxygen plays a critical role in the process of cellular respiration, which supports life by allowing organisms to convert glucose and other nutrients into energy. In this process, oxygen combines with carbon produced from the breakdown of carbohydrates, fats, and proteins, forming carbon dioxide as a byproduct. This transformation is essential for the production of adenosine triphosphate (ATP), which serves as the energy currency of the cell. The release of carbon dioxide is a natural outcome of metabolic processes, illustrating the dependency of aerobic organisms on oxygen to sustain their cellular functions.

In contrast, the other options do not accurately reflect the chemical changes associated with oxygen in supporting life. While oxygen is released during photosynthesis, this process is not the chemical transformation in question. The statements regarding oxygen transforming into hydrogen or nitrogen do not occur in biological systems and, therefore, do not play a role in supporting life either.