Question

Where is atp required in the muscle contraction process?

Answer 1

cross bridge cycle....

Answer 2

The sliding filament theory was stated to better explain the process of "cross bridge cycle" where involvement of chemical energy or Adenine Tri phosphate molecules (ATP molecules) are required for muscular contraction between actin and myosin that was given by a group of two workers A.F. Huxley and Ralph Niedergerke in 1954 and improved the theory in same year, 1954, with another worker and a collaborated work between H.E. Huxley and Jean Hanson susbsequently proposed the sliding fiilament theory.

A more improved model was given and worked out as events by Albert Szent Gyorgi and others (famous scientist). These events included six total steps which were collectively called as "Electrical and Biochemical Events in Miscualr Contraction". I will be going to filter out the main step of involvement of ATP molecules which is involved in the 4th step of the event.
In the fourth event the ATP molecules in the presence of the enzymatic molecule called "myosin ATPase" , Ca++ (Calcium ions) amd Mg++ (Magnesium ions). It further breaks it down into ADP molecules and some inorganic phosphate ions or "Pi" releasing energy into the head.