What is a primary role of protein in the body?

• A. Provides immediate energy.
• B. Stores nutrients.
• C. Builds DNA.
• D. Repairs tissues.

Answer: (D)

Proteins are essential for repairing and building the body's tissues. When you grow, exercise, or recover from an injury, the body uses amino acids from dietary protein to create new proteins that form muscles, skin, bones, and other tissues. This repairing and rebuilding function is a primary responsibility of proteins, helping maintain the structure and function of the body. While proteins also play important roles as enzymes, antibodies, and signaling molecules, these are supportive tasks that work alongside their tissue-building function. Energy, for instance, comes mainly from carbohydrates and fats, not proteins. And DNA is made from nucleic acids, not proteins, even though some proteins help with DNA-related processes. So, repairing and maintaining tissues best explains the primary role of protein.