RESPIRATION

A complex series of chemical reactions in organisms by which energy is made available for use. The end products are carbon dioxide, water and energy. aerobic respiration, which is carried out by plants and animals, is carried out in the presence of oxygen; anaerobic respiration takes place in the absence of oxygen. Many anaerobic organisms, such as many anaerobic bacteria, are obligate anaerobes and die in the presence of oxygen. Anaerobic respiration is important in biogeochemical cycles, the detoxification of waste and production of bio-energy.

[See alsocarbon assimilation, carbon cycle, nitrogen cycle, sulfur cycle, primary productivity, productivity]