The energy for muscle contraction is supplied by the enzymatic hydrolysis of ATP by ATPase present in:

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.