Q.Name the contractile proteins present in the skeletal muscle.

Skeletal muscle contraction is produced by two contractile proteins: actin, making up the thin filaments, and myosin, making up the thick filaments.

Each sarcomere of a muscle fibre contains two sets of overlapping protein filaments:

• Actin — a globular protein that polymerises into thin filaments; these thin filaments also carry the regulatory proteins troponin and tropomyosin, which control when actin sites are available for binding.
• Myosin — a motor protein that forms thick filaments, each with many projecting 'heads' that can attach to actin, pull (power stroke), and detach, using energy from ATP hydrolysis. …