Final answer:
Energy is obtained from ATP when a phosphate group is removed, forming ADP and Pi, with the release of energy due to the breakage of the high-energy phosphoanhydride bonds between the phosphate groupsACthe right answer A.
Step-by-step explanation:
What is broken off of ATP to get energy? The answer is a phosphate group. In the process of obtaining energy from Adenosine Triphosphate (ATP), a phosphate group is removed to form Adenosine Diphosphate (ADP) and an inorganic phosphate group (Pi). This reaction releases energy due to the breaking of the high-energy bond between the second and third phosphate groups, also known as the phosphoanhydride bonds. This release of energy is a critical aspect of the metabolic processes in cells, where ATP acts as the main energy currency.