Anatomy and Physiology II Practice Test

Which process is primarily concerned with the conversion of food into energy?

1. Catabolism

2. Homeostasis

3. Digestion

4. Excretion

The correct answer is: Catabolism

Catabolism refers to the metabolic process in which complex molecules from food are broken down into simpler ones. This breakdown releases energy stored within those molecules, typically in the form of adenosine triphosphate (ATP). This energy is then utilized by the body's cells to perform various functions, such as muscle contraction, nerve impulse conduction, and maintaining cellular homeostasis. In the context of the question, catabolism is the process that is predominantly focused on converting the energy within food into a usable form for the body. Though digestion plays a role in breaking down food into its components, it is the catabolic reactions that ultimately convert these components into energy. Homeostasis primarily involves maintaining a stable internal environment in the body, while excretion deals with the elimination of waste products, rather than energy conversion.