Hydrolysis is the breaking of a chemical bond, and thus the splitting of a molecule, by the addition of water which in turn is split in two ions: H+ (cation) and OH- (anion). A fragment of the target molecule gains a hydrogen ion (H+) from the split water molecule. The other fragment of the target molecule collects the hydroxyl group (OH-) of the split water molecule. One example of hydrolysis is the catalitic conversion of starch to glucose.
Hydrolysis is an important process in plants and animals. The most important example is energy metabolism and storage. All living cells require a continual supply of energy for the biosynthesis of small and macromolecules, and for the active transport of ions and molecules across cell membranes. The energy derived from the oxidation of nutrients is not used directly but, by means of a complex and long sequence of reactions, it is channeled into a special energy-storage molecule, adenosine triphosphate (ATP).