Cellular respiration is a chemical reaction that allows cells to convert food energy into chemical energy. All organisms perform some form of cellular respiration, because without the correct form of chemical energy, cells can't perform work to sustain life.
During cellular respiration, oxygen and glucose (sugar) are transformed into carbon dioxide and water. Chemical energy in the form of adenosine triphosphate (ATP) is released during the reaction.
Products in a chemical reaction are the substances that are formed during the reaction. Carbon dioxide and water are the products of cellular respiration.
Cellular respiration is a "redox" reaction, because some atoms are reduced and some are oxidized. When an atom loses electrons or hydrogen atoms, it is "oxidized." When another atom accepts those electrons or hydrogen atoms, it is "reduced." Oxidation releases energy, and reduction stores energy.
Glucose is oxidized during cellular respiration to form carbon dioxide. Oxidation releases the energy stored in the chemical bonds of the glucose molecule.
Cells need ATP to power the work they do, which includes growing, reproducing, tissue repair and specific tasks such as making antibodies or carrying oxygen throughout the body.