What is the function of ATP and explain how is it suitable for its function

ATP is a molecule called adenosine triphosphate, used to provide energy for various reactions within the cell and hence sometimes called 'universal currency' of the cell. ATP molecule is made of adenine, ribose sugar and three phosphate molecules, each of which is slightly negatively charged. During the reactions, ATP is broken down to adenosine diphosphate (ADP) and inorganic phosphate (Pi) by breaking a covalent bond between the 2nd and 3rd phosphate, releasing a small amount of energy available for the reaction. This is very useful, because of the negative charges between phosphates, it is relatively easy to break the bond, but the energy released is 'manageable' and not too large so that it could damage the cell. The ATP molecule is also very small and soluble so it can quickly diffuse across the cell to where it is needed.