The protein has direct contact with actin in a muscle in the resting state, while the _____ protein has direct contact with actin in a muscle in the contracting state.

Question

Quizplus · Accepted Answer

In the resting state of a muscle, tropomyosin covers the myosin-binding sites on actin filaments, preventing interaction between actin and myosin. During contraction, calcium ions bind to troponin, causing tropomyosin to move away from the binding sites, allowing myosin to bind to actin and initiate contraction.

The Protein Has Direct Contact with Actin in a Muscle