Answer:
Ca+ binds to troponin
Troponin removes tropomyosin from G actin
Myosin binds to actin
Myosin generates a power stroke
The sarcomere shortens
ATP recharges the myosin head
Explanation:
Contraction begins with the release of calcium ions into sarcoplasm where they bind to troponin. It moves the tropomyosin always from the myosin-binding sites present on actin. Myosin head binds to actin and forms cross-bridge followed by power stroke in which myosin head pivots to pull the thin filament past the thick filament towards the center of the sarcomere and results in shortening of the sarcomere. The myosin head binds to ATP and the cross-bridge detaches from actin. Hydrolysis of ATP charges myosin head again.
