What is the role of calcium ions in muscle contraction? (2022)

What is the role of calcium ions in muscle contraction? (2022)

Step 1: When a muscle is stimulated to contract, calcium ions are released from the sarcoplasmic reticulum into the muscle cell.
Step 2: The calcium ions bind to a protein called troponin, which is located on the actin filaments.
Step 3: When calcium binds to troponin, it causes a change in the shape (conformational change) of the troponin complex.
Step 4: This shape change moves another protein called tropomyosin away from the binding sites on actin.
Step 5: With the binding sites on actin exposed, the myosin heads can now attach to actin.
Step 6: Once myosin binds to actin, it can pull on the actin filaments, leading to muscle contraction.

No concepts available.