(N/A) Metabolism is a fundamental characteristic of all living organisms,involving various chemical reactions that sustain life.
Organisms utilize oxygen $(O_{2})$ to break down nutrient molecules,such as glucose $(C_{6}H_{12}O_{6})$,through cellular respiration to derive energy in the form of $ATP$ for performing biological activities.
As a byproduct of this oxidative breakdown,carbon dioxide $(CO_{2})$ is produced within the cells.
To maintain homeostasis,$O_{2}$ must be continuously supplied to the cells,and the metabolic waste $CO_{2}$ must be expelled from the body.
The process of exchanging atmospheric $O_{2}$ with $CO_{2}$ produced by the cells is known as breathing or ventilation,which is a critical component of the broader process of respiration.
The respiratory system facilitates this gas exchange between the atmosphere and the blood,while the circulatory system transports these gases between the lungs and the body tissues.