The following is a list of the events that occur during a muscle contraction. What is the correct sequence of these events?1. Myosin cross-bridges bind to the actin. 2. The free myosin head splits ATP. 3. Calcium ion is released from the sarcoplasmic reticulum. 4. The myosin head pivots toward the center of the sarcomere. 5. Calcium ion binds to troponin. 6. The myosin head binds an ATP molecule and detaches from the actin.

The contraction of the muscle refers to a phenomenon in which the sliding of actin over the myosin takes place in the muscle cells, permitting the body to move. For contraction of muscle to take place, three elements are needed. These are stimulation of the nervous system, the contractile proteins actin and myosin, and the energy provided by the ATP for contraction.

The correct sequence for the event of muscle contraction is as follows:

1. The release of the calcium ions from the sarcoplasmic reticulum.

2. The binding of calcium ion to troponin takes place.

3. The myosin cross-bridges combines with the actin.

4. The myosin head moves towards the middle of the sarcomere.

5. The myosin head combines with the molecule of ATP and detaches from the actin.

6. The free myosin head dissociates ATP.