So basically this ATP that is found on the myosin ahead of our thick filament, so this is a thick filament, this is our myosin head, which is basically our myosin heads. On this thick filament shown here, it is hydrolyzed and the ADP and the P that are produced remain on that myosin head. So this is step three. Now, once we hydrolyze the ATP into ADP and the phosphate and once the calcium binds onto our troponin exposing that binding site, now the binding can actually take place. So now the myosin head is oriented correctly. So what also happens when we have our hydrolysis is in this diagram, the myosin head is oriented at a 45 degree angle with respect to our thick filament.