In the initiation of muscle fiber contraction, calcium ions bind to tropomyosin, exposing active sites on actin for cross-bridge formation.

Question

In the initiation of muscle fiber contraction, calcium ions bind to tropomyosin, exposing active sites on actin for cross-bridge formation.

Quizplus · Accepted Answer

In the initiation of muscle fiber contraction, calcium ions bind to troponin, not tropomyosin. This binding causes a conformational change that moves tropomyosin away from actin's binding sites, allowing myosin to attach to actin and initiate contraction.

In the Initiation of Muscle Fiber Contraction, Calcium Ions Bind to Tropomyosin