Chemical compounds with the molecular formula C6H12O6 are known as hexoses. Common examples of hexoses include glucose, fructose and galactose. Compounds with the same molecular formula but vary in structural formulas are referred to as structural isomers.
Carbohydrates, also called sugars or saccharides, constitute one of the essential biomolecules in living organisms. Sugar compounds are comprised of three main elements, which include carbon (C), hydrogen (H) and oxygen (O). The general formula for all carbohydrates is CxH2yOy, where "x" denotes the number of carbon atoms, "2y" indicates the number of hydrogen atoms and "y" represents the number of oxygen atoms. Carbohydrates are classified into three types: monosaccharides, disaccharides and polysaccharides.
Monosaccharides are the simplest form of carbohydrates, which contain only a single sugar molecule. A 3-carbon monosaccharide, such as glyceraldehyde, is called a "triose," while a 5-carbon monosaccharide, such as deoxyribose, is known as a "pentose." A 6-carbon monosaccharide is referred to as a "hexose."
Glucose, otherwise known as "blood sugar" or "dextrose," is the bio-fuel used in cellular respiration and the source of usable energy for most organisms. It is commonly found in fruits and vegetables. Fructose, or fruit sugar, is the sweetest among all sugar compounds. It is typically found in fruits and honey. Galactose is an important component in glycolipids and glycoproteins, although it rarely exists in nature.