Which of the following classes of biomolecules typically serves as the body’s primary energy source?

Carbohydrates serve as the body’s primary energy source due to their efficient metabolism and the speed at which they can be converted into glucose. When consumed, carbohydrates break down into simpler sugars, primarily glucose, which is readily used by the body’s cells to produce ATP (adenosine triphosphate), the main energy currency of cells. This process can happen quickly, especially during high-intensity exercise when the body needs immediate energy.

While proteins and lipids can also serve as sources of energy, they are not the primary or preferred substrates for energy. Proteins are primarily used for growth and repair of tissues, while lipids are used for long-term energy storage and are metabolized at a slower rate compared to carbohydrates. Nucleic acids, on the other hand, primarily play a role in the storage and expression of genetic information and are not a significant source of energy for the body. Thus, carbohydrates are uniquely suited to meet the energy demands of the body, making them the primary energy source.