Cellular respiration is the set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste. It is the set of metabolic reactions and processes that allow organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste. The reactions involved in cellular respiration are catabolism of glucose and other food molecules into pyruvate or acetyl-CoA that are oxidized to capture electrons and produce ATP.