MUSCLE PHYSIOLOGY

Detailed explanation-1: -A protein called troponin is distributed at regular intervals on the tropomyosin. In the resting state, a subunit of troponin masks the active binding sites for myosin on the actin filaments .

Detailed explanation-2: -Tropomodulin: a cytoskeletal protein that binds to the end of erythrocyte tropomyosin and inhibits tropomyosin binding to actin.

Detailed explanation-3: -Tropomyosin covers the actin binding sites, preventing myosin from forming cross-bridges while in a resting state.

Detailed explanation-4: -Tropomyosin is a protein that winds around the chains of the actin filament and covers the myosin-binding sites to prevent actin from binding to myosin. Tropomyosin binds to troponin to form a troponin-tropomyosin complex.

Detailed explanation-5: -Specifically, troponin (the smaller protein) shifts the position of tropomyosin and moves it away from the myosin-binding sites on actin, effectively unblocking the binding site (Figure 5).