Question

Which of the following feature can't be considered as a differentiating point of myosin when compared with actin myofilaments?

• A. Thicker but longer than actin filaments
• B. Fewer than actin filaments
• C. Don't slide during muscle contraction
• D. Free at one end and jointed to Z line by other end

Answer 1

The correct option is A Thicker but longer than actin filaments

A. Thicker but longer than actin filaments

Reason: The thick filament consists mainly of myosin protein. Myosin contributes 55 percent of muscle protein by weight and found only in A-band of sarcomere. The myosin molecule is composed of six polypeptide chains, two identical heavy chains and four light chains. Myosin consists of two proteins, myosin and meromysin. Myosin thicker but longer than actin filaments. In actin filaments, found in both A and I-bands. It consists of three proteins, actin, tropomyosin and troponin. It thinner but shorter than myosin filaments.