Final answer:
ATP, adenosine triphosphate, is the molecule that provides potential energy in a readily accessible form for cells, and is vital for various cellular activities.
Step-by-step explanation:
The potential energy of organic molecules is most readily available to cells in the form of ATP (adenosine triphosphate). ATP is known as the 'energy currency' of the cell because it serves as a single unit that provides a consistent and appropriate amount of energy for various cellular processes. It is the usable form of energy which powers a variety of biological work including building complex molecules, transporting materials, and powering the motion of cilia or flagella.