Monosaccharides are the organic molecule that is the main fuel supply for cellular work. They are the most basic units of carbohydrates.
Monosaccharides are the smallest, simplest form of sugar. They are odorless, colorless, and water-soluble. Some have a sweet taste and they are the building blocks of other sugars like sucrose, glucose, fructose and polysaccharides. Lactose or milk sugar is formed when glucose and galactose combine. Maltose is malt sugar that forms when two glucose molecules combine and sucrose, also known as table sugar, is formed when glucose and fructose combine.
Most monosaccharides have the chemical formula Cx(H2O)y. Many contain either a keytone or an aldehyde functional group and most are polymers, which are long molecules that consist of building blocks linked by covalent blocks. They are identified by the number of carbons in each molecule.
Almost every living organism uses some form of monosaccharide. Vertebrates such as humans store glycogen, a form of glucose, in the muscles and liver and use them as necessary for energy. Plants store glucose in their plastids and use it for energy to produce food and animals that feed on these plants convert the plant starches to glucose to use as an energy source.