Question

muscle contraction interactive and video
drag and drop the steps of muscle contraction in order. begin with the nerve impulse (shown in bold).
first step
a nerve impulse causes calcium to be released in the muscle fiber.
calcium binds to troponin, moving tropomyosin to free up binding sites.
myosin heads pull on actin, shortening the sarcomere.
calcium levels decrease, and myosin can no longer bind to actin.
actin slides back to its original relaxed position.
last step
score: 100 % submit response notes

Explanation:

The process of muscle contraction starts with a nerve impulse causing calcium release. Calcium binds to troponin, moving tropomyosin. Myosin heads pull actin, shortening the sarcomere. Then calcium levels decrease, myosin can't bind actin, and actin slides back.

Answer:

1. A nerve impulse causes calcium to be released in the muscle fiber.
2. Calcium binds to troponin, moving tropomyosin to free up binding sites.
3. Myosin heads pull on actin, shortening the sarcomere.
4. Calcium levels decrease, and myosin can no longer bind to actin.
5. Actin slides back to its original relaxed position.