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Name the ion responsible for unmasking of active sites for myosin for crossbridge activity during muscle contraction.

Correct answer: A. Calcium

  • A. Calcium
  • B. Magnesium
  • C. Sodium
  • D. Potassiumfibrous joint.

Explanation

Calcium ion plays an important role in muscle contraction. Calcium ions bind to troponin causing a change in its shape and position.Thus, in turn alters shape and position of tropomyosin to which troponin binds. This shift exposes the active sites on F-actin molecules. Hence, myosin crossbridges are then able to bind to these active sites.

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About Support and Movement

Support and movement covers the axial and appendicular skeleton, bone structure, joints and the arrangement of skeletal muscles. Muscle contraction is explained through actin, myosin, sliding filaments, calcium ions and ATP, while arthritis is distinguished as a disorder of joints rather than a normal part of movement.

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