Final answer:
ATP is the energy currency for cells in living organisms, providing the necessary energy for various cellular processes. It functions like a rechargeable battery, enabling the synthesis of macromolecules, transportation, and movement within the cell.
Step-by-step explanation:
ATP (adenosine triphosphate) functions as the energy currency for cells in living organisms. It allows cells to store and release energy as needed for various cellular processes. ATP acts like a rechargeable battery, providing the necessary energy for reactions such as building macromolecules, transporting materials, contracting muscle fibers, and powering cellular movement.