<human>:  Explain oxygen's role in cellular respiration.
<bot>: Oxygen plays a key role in cellular respiration. In the process of cellular respiration, oxygen is used to break down organic molecules such as glucose and converts it into energy for the cell. This energy is then used to facilitate the various metabolic processes that occur in the cell. In the first stage of cellular respiration, glucose reacts with oxygen to produce carbon dioxide and water. During the second stage, the energy generated from the reaction is used to produce adenosine triphosphate (ATP). ATP is a molecule that is stored and used by the cell as a source of energy. Thus, cellular respiration requires oxygen in order to produce the energy required for the various processes in the cell.