The following is a list of the events that occur during a muscle contraction. 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 correct sequence of these events is A) 1, 3, 5, 4, 6, 2. B) 1, 4, 6, 2, 3, 5. C) 3, 5, 1, 2, 4, 6 D) 3, 5, 1, 4, 6, 2 E) 5, 1, 4, 6, 2, 3

Question

Biology

Bossy

20 March, 00:30

The following is a list of the events that occur during a muscle contraction. 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 correct sequence of these events is A) 1, 3, 5, 4, 6, 2. B) 1, 4, 6, 2, 3, 5. C) 3, 5, 1, 2, 4, 6 D) 3, 5, 1, 4, 6, 2 E) 5, 1, 4, 6, 2, 3

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Answers (1)

Know the Answer?

Deanna Hampton · Answer 1

The correct option is D. 3, 5, 1, 4, 6, 2

Explanation:

The action of muscle contraction occurs by a series of steps:

Acetylcholine is released as a result of action potential from a motor neuron. This causes the sarcoplasmic reticulum to release calcium ions. Troponin are present n the heads of actins. The calcium binds to troponin. As a result, a cross bridge is formed between the myosin and actin. The myosin head binds ATP molecule and detaches from actin. This is known as the sliding filament mechanism. The sarcomeres shorten causing muscle contraction.