Metabolism is defined as which of the following?

• A. The process of storing excess energy
• B. The process of breaking down foods and converting to energy
• C. The process of producing hormones
• D. The process of filtering waste

Answer: (B)

Metabolism is the set of chemical reactions in the body that power life, transforming the nutrients we eat into energy and the building blocks needed for growth and repair. The energy-producing aspect comes from breaking down carbohydrates, fats, and proteins and converting them into ATP through cellular respiration, which is why describing metabolism as the process of breaking down foods and converting to energy fits best. Other descriptions—storing excess energy, producing hormones, or filtering waste—relate to separate bodily functions such as energy storage, endocrine activity, and excretion, and are not the primary definition of metabolism.