What is Cellular Respiration?

Cellular Respiration : The most important of the metabolic processes, cellular respiration, provides energy for most chemical reactions in an organism. Respiration involves breakdown of the simple sugar, glucose, to provide energy. Energy for metabolic processes is available from foods other than glucose, but they must be broken down first. The first mechanism in cellular respiration is glycolysis, the breakdown of the 6-carbon glucose into two molecules of 3-carbon pyruvic acid. Glycolysis is followed by either aerobic or anaerobic respiration. Aerobic respiration occurs in the presence of oxygen. Anaerobic respiration occurs if oxygen is absent.