Question

What is the correct order of events for muscle contraction?

a. Nerve impulse is sent; Calcium channels open; Tropomyosin moves to expose binding sites on actin; Actin and myosin form linkages; Thin filaments are pulled toward center
b. Nerve impulse is sent; Tropomyosin moves to expose binding sites on actin; Calcium channels open; Actin and myosin form linkages; Thin filaments are pulled toward center
c. Nerve impulse is sent; Actin and myosin form linkages; Calcium channels open; Tropomyosin moves to expose binding sites on actin; Thin filaments are pulled toward center
d. Nerve impulse is sent; Calcium channels open; Actin and myosin form linkages; Tropomyosin moves to expose binding sites on actin; Thin filaments are pulled toward center

Answer 1

The correct order of events for muscle contraction is: Nerve impulse is sent; Calcium channels open; Actin and myosin form linkages; Tropomyosin moves to expose binding sites on actin; Thin filaments are pulled toward the center.

Step-by-step explanation:

Muscle contraction is initiated by a nerve impulse, followed by the opening of calcium channels. Tropomyosin then moves to expose binding sites on actin, allowing actin and myosin to form linkages. The final step is the pulling of thin filaments toward the center by the actin and myosin linkages.

Therefore, the correct order of events for muscle contraction is d. Nerve impulse is sent; Calcium channels open; Actin and myosin form linkages; Tropomyosin moves to expose binding sites on actin; Thin filaments are pulled toward the center.