Define the term "metabolism."

The term "metabolism" refers specifically to the sum of all chemical reactions that occur within the body. This encompasses not only the processes by which the body converts food into energy (catabolism) but also includes the synthesis of necessary substances and the management of waste products (anabolism). Metabolism is essential for maintaining the body's homeostasis, supporting growth, repair, and overall functioning.

Understanding metabolism is crucial because it highlights how the body utilizes nutrients and energy to support various physiological functions. The other options presented do refer to aspects of bodily functions but do not capture the full scope and significance of metabolism as a comprehensive set of biochemical processes that sustain life.