Here's why:
* Cellular respiration is the process by which cells use oxygen to break down glucose (sugar) and release energy in the form of ATP (adenosine triphosphate). This process produces carbon dioxide as a waste product.
* Oxygen is needed for the process of cellular respiration, and carbon dioxide is a byproduct.
* Gas exchange refers to the movement of oxygen into the cells and carbon dioxide out of the cells.
Important Note: While cellular respiration is the process that takes place within cells, the overall exchange of gases between the body and the environment is called respiration.
