Which one of the following sets of ions is necessary in the chemical events for muscle contraction?
Options
(a) Na⁺ and K⁺
(b) Na⁺ and Ca⁺⁺ ions
(c) Na⁺ and Mg⁺⁺ ions
(d) Ca⁺⁺, K⁺ and Mg⁺⁺ ions
Correct Answer:
Ca⁺⁺, K⁺ and Mg⁺⁺ ions
Explanation:
Biochemical and electrical events occurring during muscle contraction were studied by Albert Szent-Gyorogyi (1942). Muscle fibre is generally stimulated by the release of acetylcholine from the neuromotor junction. This depolarises the sarcolemma and develops an action potential with the reversal of flow of ions, more Na⁺ towards interior than K⁺ pass out. Sarcoplasmic reticulum release Ca²⁺ ions. Calcium ions remove troponin-tropomyosin block overactive site of actin filaments.ATP is required along with Mg