A lipase is a water-soluble enzyme that catalyzes the hydrolysis of ester chemical bonds in water-insoluble lipid substrates. Lipases are a subclass of the esterases. They perform essential roles in the digestion, transport and processing of dietary lipids in most, if not all, living organisms. Genes encoding lipases are even present in certain viruses. Description: Human pancreas. Alternative Names: Lipase Antigen