Question

ATP-ase needed for muscle contraction is present over

• A. Aetinin
• B. Troponin
• C. Myosin
• D. Actin

Answer 1

The correct option is C Myosin

ATPase needed for muscle contraction is present over the myosin. Myosin binds to actin at a binding site. Myosin has another binding site for ATP at which enzymatic activity of myosin ATPase hydrolyzes ATP to ADP which releases an inorganic phosphate molecule and energy. The energy released during ATP hydrolysis changes the angle of the myosin head into a cocked position. The myosin head is then in a position for further movement possessing potential energy. The enzyme myosin ATPase catalyses the reaction in the presence of Ca${}^{2+}$ and Mg${}^{2+}$. So, the correct answer is 'Myosin'.