Question

ATP for muscle contraction can be formed by

• A. Aerobic respiration
• B. Glycolysis
• C. Creatine phosphate breakdown
• D. All of the above

Answer 1

The correct option is D All of the above

• A sarcomere is the basic unit of muscle tissue in both cardiac and skeletal muscle. 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.
  
• 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'.