_________ are the nutrients needed for energy to run every function within the body.

• A. Proteins
• B. Carbohydrates
• C. Fats
• D. Vitamins

Answer: (B)

Carbohydrates provide the body’s primary energy source. When eaten, they are broken down into glucose, which fuels cellular respiration and ATP production in every cell. This rapid glucose supply supports all bodily functions, including brain activity, muscle movement, and organ operation. The body does store some glucose as glycogen in the liver and muscles for quick reuse, but when quick energy is needed, carbohydrates are the go-to fuel. Fats are also a major energy source, especially for longer, slower activities, but they’re mobilized more slowly. Proteins mainly serve as building blocks for tissues and only contribute energy when carbohydrate and fat stores are low. Vitamins don’t provide energy themselves; they help enzymes carry out metabolic reactions.