What is the process of moving oxygen and carrying carbon dioxide between blood and cells called?

The process of moving oxygen into cells and carrying carbon dioxide out of cells is known as cellular respiration. This intricate biochemical process occurs at the cellular level where cells utilize oxygen to convert glucose into energy, producing carbon dioxide as a byproduct. Cells take in oxygen from the bloodstream, which is transported by red blood cells and subsequently utilized within mitochondria to generate adenosine triphosphate (ATP), the energy currency of the cell.

In the context of this question, cellular respiration is fundamental because it underpins the vital exchanges that sustain bodily functions, involving both the intake of oxygen necessary for energy production and the removal of carbon dioxide, which is a waste product of this metabolic process. This terminology encapsulates both the physiological function of gas exchange and its metabolic implications, making it the most accurate choice among the options provided.

While the other terms do relate to aspects of respiratory and circulatory functions, they don't directly capture this specific cellular mechanism. The respiratory cycle generally pertains more to the processes involved in breathing, while metabolism encompasses a broader range of biochemical activities within the body. Circulation refers to the movement of blood through the body's vessels, facilitating the transport of gases, nutrients, and wastes, but does not specifically define the cellular exchange characteristic of cellular respiration