D. A phosphate group is removed from atp to form adp.
Explanation:
ATP normally produces energy by breaking down the weak phosphate cell present. The energy delivered due to the breaking down of the phosphate cell is then applied. The ATP is modified to ADP. Whenever a cell feels the necessity for energy it loses a phosphate to assume the energy. It is an automatic and ongoing process. The weak bond between the secondary and the third phosphate is always targeted for converting ATP to ADP. This is the reason ATP is reflected in the main energy money for the cell.
