Minerals and Muscle Contraction

Calcium is essential for muscle contraction: it binds to troponin during the contraction process, enabling the interaction between actin and myosin filaments. Sodium (and potassium) are critical for muscle contraction as they maintain the action potential and ion gradients necessary for nerve impulses that trigger muscle contraction. Iron's primary role is in oxygen transport via hemoglobin; while oxygen is needed for muscle ATP production, iron is not directly required for the mechanical contraction process itself. Therefore, calcium and sodium are directly involved in muscle contraction, but iron is not. > Muscle Contraction = Ca²⁺ (actin-myosin interaction) + Na⁺ (action potential). Answer: (c).