During which part of aerobic respiration is oxygen used?

Cellular respiration converts the reactants' oxygen and glucose into carbon dioxide, water, and energy. The re?

• Cellular respiration converts the reactants' oxygen and glucose into carbon dioxide, water, and energy. The reverse reaction of photosynthesis converts reactants of carbon dioxide and water into oxygen and glucose. These two reactions are part of which biogeochemical cycle? Carbon cycle Nitrogen cycle Phosphorus cycle Water cycle

• Answer:

  These reactions are part of the carbon cycle. The carbon cycle describes the exchange, in part, of carbon into and out of inorganic and organic reservoirs. Photosynthesis brings it in (CO2 -> sugar) and respiration send carbon back out. While water is a component of these cycles as well, the amount of water that enters living organisms is such a tiny fraction compared to the amount moved by evaporation and precipitation that it is not considered part of the water cycle. There is no nitrogen or phosphorus involved in these reactions so they are not part of those cycles either.