HUMAN PHYSIOLOGY
LOCOMOTION AND MOVEMENT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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ATP is broken down
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ATP is formed
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GTP is broken down
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none of the above
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Detailed explanation-1: -The ATP is broken down to ADP and phosphate, releasing energy, which is stored in the myosin head and which is later used for binding of myosin and actin which leads to muscle contraction.
Detailed explanation-2: -The ATP is hydrolyzed into ADP and inorganic phosphate (Pi) by the enzyme ATPase. The energy released during ATP hydrolysis changes the angle of the myosin head into a “cocked” position, ready to bind to actin if the sites are available. ADP and Pi remain attached; myosin is in its high energy configuration.
Detailed explanation-3: -Muscle contraction occurs when the thin actin and thick myosin filaments slide past each other. It is generally assumed that this process is driven by cross-bridges which extend from the myosin filaments and cyclically interact with the actin filaments as ATP is hydrolysed.