D carbohydrate

Carbohydrates exist in a variety of isomeric forms, they have stereoisomers, molecules that have the same molecular formula but differ in their spatial arrangement. Carbohydrates can have a D-configuration or L-configuation, known as enantiomers, these are mirror images of each other. The D/L configuation is dictated by the assymmetrical carbon in the carbohydrate carbon chain which is furthest from the aldohyde or ketone group. Most of the carbohydrates found in vertebrates are in the D-configuation. An example is the hexose carbohydrate, D-glucose, the carbon5 (C5) is the furtherest assymmetrical carbon from the aldehyde group (C1), CH2OH group on the C5 lies in the equatorial plane and the Hydrogen is in the axial plane. In its enantimer L-glucose this configuration is reverse, the Hydrogen in the equatorial plane and the CH2OH roup in the axial.