Beta-glucose

Beta-glucose is a cyclic, six carbon sugar, formed from glucose, and can polymerise to make cellulose, an essential polysaccharide used in the structure of plants.

Glucose it a simple monosaccharide, chemical formulae: C₆H₁₂O₆, and is an important carbohydrate which can provide energy or structure to organisms through its various forms.

In glucose, carbons 2, 3, 4 and 5 each have a hydroxyl group, and the direction these groups come off their chiral carbon decides the type of monosaccharide. Two of the combinations give the two glucose stereoisomers: D and L. These two isomers are mirror images of each other. Other arrangements of the hydroxyl groups give different sugars, and all of these different sugars are epimers of each other.

Glucose can form a cyclic structure by a reaction between C1 and C2. The cyclic version can come in two forms for each type of glucose: alpha and beta. These two isomers exist because the formation of cyclic glucose creates an asymmetric carbon at C1. This stereoisomerism at C1 is the cause for the two forms.

Repeated condensation reactions between C1 and C4 of two D-beta-glucose molecules forms a covalent glycosidic bond, creating a disaccharide, and with further polymerising can form cellulose - the most abundant organic molecule on Earth.

Cellulose is formed by 1,4 glycosidic bonds between hundreds of D-beta-glucose molecules and hydrogen bonds between the layers of the polysaccharide. This creates a highly organised crystalline structure, which plants use to maintain cell wall structure. Cellulose can be hydrolysed with enzymes back to glucose.