Cellular respiration products are water, carbon dioxide, heat and adenosine triphosphate or ATP. This applies to aerobic respiration. For anaerobic respiration, cellular respiration products are alcohol or lactic acid, carbon dioxide and ATP. This process occurs in four stages: glycolysis, the transition reaction, the Krebs cycle and the electron transport chain.
Aerobic respiration requires oxygen and food molecules like glucose. Its products include energy in the form of ATP, which is stored in cells for use when required, and heat, which is released during aerobic respiration. Anaerobic respiration requires food molecules, such as glucose, but not oxygen. During anaerobic respiration, fungal and plant cells produce alcohol. Animal cells, including human cells, produce lactic acid. An example of anaerobic respiration is yeast fermentation, which produces ethyl alcohol or ethanol, a type of alcohol.
During glycolysis, a glucose molecule is broken into two molecules of pyruvic acid. This stage produces two molecules of ATP for every molecule of glucose used. Pyruvic acid is then converted to acetyl CoA during the transition reaction. This stage occurs in the mitochondria of the cell.
During the Krebs cycle, hydrogen is stripped from the acetyl CoA. This stage produces a lot of NADH, which is needed for the electron transport chain, as well as four molecules of ATP for every glucose used. Finally, NADH carries the electrons from the hydrogen down the electron transport chain. This stage produces 32 ATP for every glucose molecule.