The general chemical formula for disaccharides is Cn(H2O)m. As a disaccharide, sucrose is composed of the monosaccharides glucose and fructose in the molecular formula C11H22O11. Other common disaccharides include lactose, maltose and trehalose.
Lactose, also known as milk sugar, is composed of the monosaccharides galactose and glucose. Lactose-intolerant people cannot break down lactose, as they lack the digestive enzyme lactase.
Maltose is a disaccharide composed of two molecules of glucose. Maltose is formed by the breakdown of starch. Plants use starch to store sugars.
Trehalose is also composed of two molecules of glucose, but these molecules are arranged differently than maltose. Trehalose has a mildly sweet taste in comparison to sucrose.