Question

fill in the blank question

in a thin filament, each tropomyosin molecule has a small calcium-binding protein called bound to it.

Explanation:

Identify the components of thin filaments

Using the Thin Filaments knowledge point

• Thin filaments are primarily composed of actin, tropomyosin, and troponin.
• Tropomyosin is a regulatory, thread-like protein that blocks the active sites on actin.
• Troponin is a smaller, three-subunit calcium-binding protein complex attached to tropomyosin.

Determine the specific calcium-binding protein

• When calcium ions bind to troponin, it undergoes a conformational change.
• This change pulls tropomyosin away from the active sites on actin, allowing myosin heads to bind and initiate muscle contraction.
• Therefore, the small calcium-binding protein bound to each tropomyosin molecule is troponin.

Answer:

In a thin filament, each tropomyosin molecule has a small calcium-binding protein called <blank>troponin</blank> bound to it.