Which term best matches the concept of chemical reactions sustaining life?

• A. Sedative-Hypnotic
• B. Basal Metabolic Rate
• C. Metabolism
• D. Compensation

Answer: (C)

Metabolism is the set of all chemical reactions in living organisms that keep them alive, from breaking down nutrients to releasing energy to building new cellular components. These interconnected pathways include both catabolic reactions that release energy and anabolic reactions that use that energy to synthesize biomolecules, membranes, and other structures, sustaining cell function and maintaining homeostasis. This broad concept best fits the idea of chemical reactions sustaining life. A resting energy expenditure, or basal metabolic rate, describes just how much energy the body uses at rest, not the entire network of reactions. A sedative-hypnotic relates to drugs that affect the central nervous system, and compensation refers to adaptive responses in physiology, not the overall metabolic framework.