Question

when skeletal muscle is at rest, which regulatory protein prevents thin and thick filament interaction?
a.) troponin
b.) actin
c.) myosin
d.) tropomyosin

Explanation:

When skeletal muscle is at rest, tropomyosin covers the myosin - binding sites on actin. This prevents the interaction between thin (actin) and thick (myosin) filaments. Troponin helps in the regulation by binding to calcium and causing a conformational change in tropomyosin. Actin is the thin filament protein and myosin is the thick filament protein.

Answer:

d. Tropomyosin