Disaccharide
A disaccharide (also called a double sugar or biose) is the sugar formed when two monosaccharides (simple sugars) are joined. Like monosaccharides, disaccharides are soluble in water. Three common examples are sucrose, lactose, and maltose.
Disaccharides are one of the four chemical groupings of carbohydrates (monosaccharides, disaccharides, oligosaccharides, and polysaccharides). The most common types of disaccharides—sucrose, lactose, and maltose—have twelve carbon atoms, with the general formula C12H22O11. The differences in the disaccharides are due to atomic arrangements within the molecule.