Question

which mineral is required for electrolytes involved in muscle contractions?
a calcium
b sodium
c iron
d iodine

Explanation:

Calcium is crucial for muscle contractions as it binds to troponin, causing a conformational change that exposes the myosin - binding sites on actin filaments, enabling muscle contraction. Sodium is mainly involved in nerve impulse transmission and maintaining osmotic balance. Iron is essential for oxygen - carrying in hemoglobin. Iodine is important for thyroid hormone synthesis.

Answer:

A. Calcium