Organic compounds that are not polypeptides but are necessary for enzymes to properly function are called a

Coenzymes are tiny and microscopic, nonproteinaceous molecules that gives a transfer site for a functioning enzyme. They are intermediate carriers of an atom or group of atoms, allowing a reaction to occur. Coenzymes are not  part of an enzyme's structure, They are sometimes referred to as cosubstrates.

after a the power stroke, adp is released, but the cross-bridge formed is still in place. atp then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site.