What is the primary output of cellular respiration?

Cellular respiration is a metabolic process that takes place in cells to convert biochemical energy from nutrients into adenosine triphosphate (ATP), which serves as the primary energy currency of the cell. During this process, glucose—derived from food—undergoes a series of chemical reactions to release energy. This energy is captured in the form of ATP, which cells use to power various biological functions, such as muscle contraction, active transport across membranes, and biochemical synthesis.

The reactions of cellular respiration involve not only the breakdown of glucose but also the consumption of oxygen and the production of byproducts, namely carbon dioxide and water. While oxygen is utilized during the electron transport chain and carbon dioxide is released as a waste product, the main goal of cellular respiration is to produce ATP. Thus, ATP is the key output that indicates the successful conversion of energy from nutrients for cellular functions, making it the correct answer in this context.