What is the significance of the binding of calcium ions to a subunit of troponin in muscle contraction?

What is the significance of the binding of calcium ions to a subunit of troponin in muscle contraction?
  1. It leads to the binding of myosin to the actin filaments
  2. It helps in ATP production
  3. It masks the active sites for myosin
  4. It causes the release of ADP and Pi from myosin

Solution

The binding of calcium ions to a subunit of troponin causes the removal of the masking of the active sites for myosin. This allows the myosin head to bind to the exposed active sites on actin, forming a cross bridge and causing contraction of the muscle.

Asked in: NCERT

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