What is the Role of the Sarcoplasmic Reticulum in Muscle

Question

What is the role of the sarcoplasmic reticulum in muscle contraction? A) It stores Ca²⁺ ions for release during contraction. B) It surrounds and protects the muscle filaments. C) It provides sites of ATP synthesis. D) It depolarizes when stimulated by an impulse. E) It synthesizes actin and myosin filaments.

Accepted Answer

The sarcoplasmic reticulum stores and releases calcium ions, which are necessary for muscle contraction. When a muscle fiber is stimulated, the sarcoplasmic reticulum releases the calcium ions, allowing them to bind to the myofilaments and initiate the contraction process.