"Animals, plants, and fungi often have many different organs whose different functions are integrated, enabling multicellular organisms to maintain themselves, grow, and reproduce. Two or more tissues that work together to get a job done form an organ. A group of organs that works together to perform a certain job is an organ system. Organ systems found in plants, animals, and other multicellular organisms allow these organisms to function more efficiently."
ATP provides the cell with a way to handle energy in an efficient manner. The molecule can be charged, stored, and used as needed. Moreover, the energy from hydrolyzing ATP is delivered as a consistent amount.
