This document discusses various disaccharides. It describes the structures and properties of sucrose, lactose, maltose, and isomaltose. Sucrose is a non-reducing disaccharide of glucose and fructose linked by an alpha-1,2 glycosidic bond. Lactose is a reducing disaccharide found in milk consisting of glucose and galactose linked by a beta-1,4 bond. Maltose contains two glucose units linked by an alpha-1,4 bond, while isomaltose contains two glucose units linked by an alpha-1,6 bond. The document also provides details on the hydrolysis and properties of each disaccharide.