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Multiple Choice
The thin myofilaments of skeletal muscle are composed chiefly of __________.
A
tropomyosin
B
troponin
C
myosin
D
actin
Verified step by step guidance
1
Begin by understanding the structure of skeletal muscle. Skeletal muscle fibers contain myofibrils, which are composed of repeating units called sarcomeres.
Each sarcomere is made up of thick and thin myofilaments. The thick filaments are primarily composed of the protein myosin.
The thin filaments, on the other hand, are primarily composed of the protein actin. Actin molecules form a helical structure that serves as the backbone of the thin filament.
In addition to actin, the thin filaments also contain regulatory proteins such as tropomyosin and troponin. Tropomyosin covers the binding sites on actin, while troponin regulates the position of tropomyosin.
Therefore, when identifying the chief component of thin myofilaments in skeletal muscle, focus on actin as the primary structural protein.