What is the process by which glucose and other nutrients are converted into energy?

The process by which glucose and other nutrients are converted into energy is best described as metabolism. Metabolism encompasses all the biochemical reactions that occur within a body, including both anabolic processes, which build molecules and store energy, and catabolic processes, which break down molecules and release energy.

Specifically, within metabolism, glucose undergoes a series of chemical transformations through processes such as glycolysis, the Krebs cycle, and oxidative phosphorylation, ultimately resulting in the production of adenosine triphosphate (ATP), the primary energy currency of cells. This ability to transform stored energy from food into usable energy is critical for all cellular functions.

While digestion and absorption are important processes that precede metabolism—digestion breaks down food into smaller components, and absorption involves the uptake of these nutrients into the bloodstream—metabolism is the term that directly refers to the conversion of these nutrients into energy. Respiration, while related to the energy production process, specifically refers to the exchange of gases (oxygen and carbon dioxide) rather than directly to the biochemical conversion of nutrients into energy.