Monosaccharides, also called simple sugars, are the most basic units of carbohydrates. They are fundamental units of carbohydrates and cannot be further hydrolyzed to simpler compounds. The general formula is CnH2nOn. They are the simplest form of sugar and are usually colorless, water-soluble, and crystalline solids. Some monosaccharides have a sweet taste. Examples of monosaccharides include glucose (dextrose), fructose (levulose), and galactose. Monosaccharides are the building blocks of disaccharides and polysaccharides. Further, each carbon atom that supports a hydroxyl group is chiral, giving rise to a number of isomeric forms, all with the same chemical formula. For instance, galactose and glucose are both aldohexoses, but have different physical structures and chemical properties.