Which term signifies the destructive phase of metabolism?

The term that signifies the destructive phase of metabolism is catabolism. Catabolism refers to the biochemical processes that break down complex molecules into simpler ones, resulting in the release of energy. This process is essential for the body as it utilizes the energy released from these reactions to fuel various physiological functions and to support anabolic processes, where smaller molecules are built up into larger, more complex ones.

In contrast, while the other terms have important roles in biological processes, they do not pertain to the destructive phase of metabolism. Anabolism is the opposite of catabolism; it refers to the process of building up larger molecules from smaller ones, which typically requires energy. Homeostasis describes the body's ability to maintain stable internal conditions, and metaplasia is a process involving the alteration of one differentiated cell type to another, often in response to chronic injury or irritation. These definitions clarify why catabolism is uniquely identified as the destructive aspect of metabolic activities.