Glyceraldehyde isomer models. Molecular models of the two isomeric forms of glyceraldehyde. D- glyceraldehyde (left) has a hydroxyl group (OH) on the right side of the asymmetric carbon atom, whereas L-glyceraldehyde has an OH group on the left side. Carbon atoms are black, oxygen atoms are red, and hydrogen atoms are white. Glyceraldehyde is a sweet, colourless, crystalline solid. It is an intermediate compound in carbohydrate metabolism.