In skeletal muscle sarcomeres, thick filaments are primarily composed of which protein?

• A. Myosin
• B. Tropomyosin
• C. Troponin
• D. Actin

Answer: (A)

Verified step by step guidance

1. Understand the structure of a sarcomere, which is the basic contractile unit of skeletal muscle, composed of thick and thin filaments.
2. Recall that thick filaments in the sarcomere are primarily made up of the motor protein responsible for muscle contraction.
3. Identify the main protein in thick filaments, which interacts with thin filaments to generate force during contraction.
4. Recognize that myosin is the protein forming the thick filaments, while actin, tropomyosin, and troponin are associated with thin filaments.
5. Conclude that the thick filaments are primarily composed of myosin based on their role and protein composition.