ANATOMY

Detailed explanation-1: -So, the correct answer is ‘Troponin and tropomyosin’.

Detailed explanation-2: -The role of the regulatory proteins tropomyosin (Tm) and troponin (Tn) in muscle contraction has been viewed as controlling only the access of the cross-bridge (control of the rate of strong cross-bridge binding) to the thin filament (Huxley, 1972).

Detailed explanation-3: -In vertebrate striated muscle, troponin-tropomyosin is responsible, in part, not only for transducing the effect of calcium on contractile protein activation, but also for inhibiting actin and myosin interaction when calcium is absent.

Detailed explanation-4: -So, the correct answer is ‘Troponin and tropomyosin’.

Detailed explanation-5: -Tropomyosin and troponin prevent myosin from binding to actin while the muscle is in a resting state.