Glucose is a hexose sugar.It consists of six carbon atoms and has the molecular formula C6H12O6.There are two isomers of glucose: alpha-glucose and beta-glucose.The hydroxyl group on carbon atom 1 are in different positions: above or below the ring of carbon atoms.Glucose is sweet-tasting and soluble in water.Glucose molecules are polar. Hydrogen bonds can form between the hydroxyl groups and water molecules.