Which of the following describes the relationship between metabolism and energy?

Metabolism refers to the set of life-sustaining chemical reactions in organisms, which includes both the processes of breaking down food (catabolism) and building up cellular components (anabolism). Answer B accurately describes this relationship by stating that metabolism utilizes energy to perform work. In essence, the body transforms the energy obtained from food into forms that can be used for various biological functions, such as muscle contractions, nerve impulses, and cellular repair.

This energy conversion is central to metabolism, as it enables all bodily functions to occur. The nutrients consumed are metabolized, leading to the production of ATP (adenosine triphosphate), which is the high-energy molecule that fuels many cellular activities. Hence, the role of metabolism in utilizing energy is fundamental to sustaining life.

The other options do not accurately capture the relationship. For instance, stating that metabolism creates energy in a vacuum suggests a misunderstanding of thermodynamics and the law of conservation of energy, which indicates that energy cannot be created or destroyed but only transformed. Furthermore, saying that metabolism expends energy without producing ATP overlooks the essential aspect of energy production within metabolic pathways. Finally, claiming that metabolism only occurs when energy is present does not consider the fact that metabolic pathways continually cycle, even when energy levels