What does metabolism encompass?

Metabolism encompasses all chemical reactions occurring within an organism, which include both anabolic and catabolic processes. Anabolic reactions are those that build complex molecules from simpler ones, such as the synthesis of proteins from amino acids, while catabolic reactions break down complex molecules into simpler ones, releasing energy in the process, such as the breakdown of glucose during cellular respiration.

This comprehensive definition emphasizes that metabolism is not limited to just one type of reaction, but rather includes the entirety of biochemical processes that sustain life. By managing the conversion of energy and matter through these chemical reactions, metabolism plays a crucial role in maintaining cellular functions, growth, and homeostasis in organisms. Hence, the correct choice highlights the broad scope of metabolism, encompassing all necessary reactions for the organism's survival and functionality.