GENERAL HISTOLOGY

Detailed explanation-1: -Muscle contraction thus results from an interaction between the actin and myosin filaments that generates their movement relative to one another. The molecular basis for this interaction is the binding of myosin to actin filaments, allowing myosin to function as a motor that drives filament sliding.

Detailed explanation-2: -The walking motion of the myosin heads along the actin strand is responsible for muscle contraction, bringing the ends of the sarcomeres closer together and shortening the length of the muscle fiber.

Detailed explanation-3: -The impulse for contraction reaches the muscle through nerves, which triggers the release of calcium ions into the cytoplasm. Calcium ion is responsible for binding actin and myosin filaments.

Detailed explanation-4: -(1) Calcium binds to troponin C, causing the conformational shift in tropomyosin that reveals myosin-binding sites on actin. (2) ATP then binds to myosin. (3) ATP is then hydrolyzed. (4) A cross-bridge forms and myosin binds to a new position on actin.