Which body system benefits from amino acids provided by protein for growth, repair, and maintenance?

• A. Respiratory system.
• B. Musculoskeletal system.
• C. Digestive system.
• D. Nervous system.

Answer: (B)

Amino acids from dietary protein are the building blocks for tissue growth, repair, and maintenance. The musculoskeletal system—the muscles, bones, tendons, and cartilage—relies on these amino acids to grow larger and stronger, repair muscle fibers after activity, and keep connective tissues robust. Muscle proteins like actin and myosin are synthesized from amino acids, enabling hypertrophy and recovery after exercise, while collagen and other proteins reinforce bone and connective tissues to maintain structural integrity. Other systems do use amino acids for specialized roles, but the most direct and broad impact of providing amino acids for ongoing growth and repair is on the musculoskeletal system.