During muscle contraction, binding sites for myosin are uncovered by the movement of ___________.Multiple ChoicetropomyosinADPactin myofilamentstroponin

Break Down the Problem

The question asks for the specific structure that uncovers the binding sites for myosin during muscle contraction from the given options.

Relevant Concepts

In muscle contraction, the proteins involved include:

1. Tropomyosin: A protein that blocks the myosin binding sites on actin filaments.
2. Troponin: A complex linked to tropomyosin that binds calcium ions and causes a conformational change to remove tropomyosin from the binding sites.

Analysis and Detail

During contraction, when calcium ions are released into the muscle fibers, they bind to troponin, resulting in a conformational change in the troponin complex. This change moves tropomyosin away from the myosin binding sites on the actin filaments, allowing the myosin heads to attach to actin.

• Tropomyosin primarily functions to block these binding sites.
• Troponin is the protein that, upon binding calcium, causes the movement of tropomyosin.

Verify and Summarize

Therefore, the correct answer is troponin, as it directly facilitates the movement of tropomyosin.

Final Answer

Troponin