Which of the following is a function of carbohydrates in animals?

Carbohydrates play a crucial role as a primary source of energy in animals. When consumed, carbohydrates are broken down into glucose, which is then used by cells to generate ATP (adenosine triphosphate) through cellular respiration. This process provides the energy necessary for various bodily functions, including muscle contraction, digestion, and even brain activity.

While other options outline important biological functions—such as cellular repair, immune defense, and hormone production—these roles are typically fulfilled by other macromolecules. For instance, proteins are more directly involved in repairing cellular structures and functioning in the immune system, while hormones are generally synthesized from proteins or lipids. Carbohydrates, however, are specifically tailored for energy provision, making them vital to the survival and functioning of animals.