Question

The contractile protein of skeletal muscle involving ATPase activity is

• A. Troponin
• B. Myosin
• C. Tropomyosin
• D. Alpha - actinin

Answer 1

The correct option is B Myosin

Myosin is a contractile protein that interacts with actin to bring about the contraction of a muscle or cell movement. The type of myosin molecule found in muscle fibers consists of a tail, by which aggregates with other myosin molecules to form so-called thick filaments, and a globular head, which has sites for the attachment of actin and ATP molecule. The myosin head also has ATPase activity which requires $M{g}^{2+}$. Troponin and tropomyosin associate with actin (thin) filament.
The thin filament is made of actin, tropomyosin, and troponin.Troponin is attached to the protein tropomyosin and lies within the groove between actin filaments in muscle tissue. Tropomyosin is a protein involved in skeletal muscle contraction and that wraps around actin and prevents myosin from grabbing it.
Actinin is a microfilament protein. α-Actinin is necessary for the attachment of actin filaments to the Z-lines in skeletal muscle cells.