Monosaccharides are the building block of carbohydrates, they include examples such as glucose, fructose, and galactose among others.
Two monosaccharides join to form a disaccharide such as maltose and sucrose while many monosaccharides join to form polysaccharides such as starch and cellulose.
Monosaccharides are made up of functional groups; carbonyl group,-COO and hydroxyl group also known as alcohol, OH.