'''Respiration''' (or just [[breath]]ing) is defined as the transport of [http://en.wikipedia.org/wiki/Oxygen oxygen] from the outside air to the [[cells]] within [http://en.wikipedia.org/wiki/Tissue_(biology) tissues], and the transport of [http://en.wikipedia.org/wiki/Carbon_dioxide carbon dioxide] in the [[opposite]] direction. This is in contrast to the biochemical definition of respiration, which refers to [http://en.wikipedia.org/wiki/Cellular_respiration cellular respiration]: the metabolic [[process]] by which an [[organism]] obtains [[energy]] by reacting oxygen with glucose to give water, carbon dioxide and ATP (energy). Although physiologic respiration is [[necessary]] to sustain cellular respiration and thus life in [[animals]], the processes are distinct: cellular respiration takes place in [[individual]] cells of the animal, while physiologic respiration concerns the bulk [[flow]] and transport of metabolites between the [[organism]] and the external [[environment]]. | '''Respiration''' (or just [[breath]]ing) is defined as the transport of [http://en.wikipedia.org/wiki/Oxygen oxygen] from the outside air to the [[cells]] within [http://en.wikipedia.org/wiki/Tissue_(biology) tissues], and the transport of [http://en.wikipedia.org/wiki/Carbon_dioxide carbon dioxide] in the [[opposite]] direction. This is in contrast to the biochemical definition of respiration, which refers to [http://en.wikipedia.org/wiki/Cellular_respiration cellular respiration]: the metabolic [[process]] by which an [[organism]] obtains [[energy]] by reacting oxygen with glucose to give water, carbon dioxide and ATP (energy). Although physiologic respiration is [[necessary]] to sustain cellular respiration and thus life in [[animals]], the processes are distinct: cellular respiration takes place in [[individual]] cells of the animal, while physiologic respiration concerns the bulk [[flow]] and transport of metabolites between the [[organism]] and the external [[environment]]. |