Available oxygen
Available oxygen is the amount of oxygen present at a specific time that can be used in aerobic cellular respiration.
Aerobic cellular respiration is a metabolic process that occurs within the cells of organisms. In this process, oxygen is used in the mitochondria to chemically convert organic molecules such as glucose into adenosine triphosphate (ATP), with the release of water and carbon dioxide as waste products. Aerobic cellular respiration results in a larger amount of energy (ATP) which is used by the cell to perform its activities.