Metabolic process in animals and plants by which organic substances are broken down into simpler products with the release of energy, which is incorporated into ATP and subsequently used for other metabolic processes. In most plants and animals, respiration requires oxygen (aerobic respiration), and carbon dioxide is an end product. Anaerobic respiration is the breakdown of food components such as glucose to yield energy in the form of ATP in the absence of oxygen. Anaerobic respiration in yeasts produces ethanol as a waste product, a process that is the basis of manufacturing alcoholic beverages.