Sugar is a compound made up of three atoms, carbon, hydrogen and oxygen, with the molecular formula C12H22O11. Elements are known as forms of matter made up of the same kinds of atoms, while compounds can come from the same or different types of atoms or elements chemically bonded together. A molecule is a group of atoms bonded together and represents the smallest basic unit of a compound that can participate in a chemical reaction, and sugar fits this definition. Sugar generally refers to sucrose. Sucrose is a disaccharide, consisting of two sugars, glucose and fructose (both monosaccharides).