Muta-rotation: α-and β-forms show specific rotation of + 113° of glucose and + 19° respectively. It is the change in the optical rotation because of the change in the equilibrium between two anomers, when the corresponding stereocenters interconvert. In aqueous solution, both the forms of glucose show muta-rotation from 1130 to 530 while β-form shows a muta-rotation from 19° to 53°. At equilibrium, β-D glucose is the most stable (64%), α-D glucose occupies only 36%.
The cyclic structure of glucose was proposed by Haworth. Pyranose cyclic structure of glucose has 05 carbons whereas Furanose structure has 06 carbons.
Maltose (Disaccharide) = Glucose + Glucose
Sucrose = Glucose + Fructose
Lactose = Glucose + Galactose.
Polysaccharide can be divided into 03 major classics:
- Starch or plant carbohydrate
- Glycogen or animal carbohydrate