This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'The energy for muscle contraction is supplied by the enzymatic hydrolysis of ATP by ATPase present in: \nSelect and explain. \nA. Heavy meromyosin, B. Light meromyosin, C. Tropomyosin, D. Troponin', 'role': 'user'}, {'content': "Answer: A \nExplanation: The energy for muscle contraction is supplied by the enzymatic hydrolysis of ATP by ATPase present in heavy meromyosin. Two strands of heavy meromyosin are found in each myosin head - one of which is folded over as a protein mass. Light meromyosin is also found in myosin but is not involved in splitting ATP. Troponin and tropomyosin are located on the actin filament. Ref: Murray R.K. (2011). Chapter 49. Muscle & the Cytoskeleton. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.", 'role': 'assistant'}]