Question

Which of the following is not involved in muscle contraction?

• A. Creatine phosphokinase
• B. Troponin
• C. Calcium ions
• D. All of these are involved in muscle contraction

Answer 1

Answer: (D)

All of these are involved in muscle contraction

• Myofibril activity is required for muscle contraction on the molecular level.
  
• When ATP binds to myosin, it separates from the actin of the myofibril, which causes a contraction.
• Creatine phosphokinase helps in the regeneration of ATP.
• H zone disappears and Z zone moves towards each other.
• The muscle contraction cycle is triggered by calcium ions binding to the protein complex troponin, exposing the active-binding sites on the actin.
• ATP then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site.

So, the correct option is 'All of these' are involved in muscle contraction'.