Fischer diagrams:

A chiral molecule can be presented through a Fischer diagram. The molecule is drawn like that the carbon chain is vertical along with the functional group located at the top. The vertical C-C bonds from the asymmetric center point into the page whereas the horizontal bonds from the asymmetric center emerge of the page. This is generally drawn without identifying the wedged and hatched bonds.

The Fischer diagrams of alanine permit the structures to be described as L- or D- from the position of the amino group. If the amino group is to the left, then it is the L- enantiomer. If it is located to the right, it is the D-enantiomer. This is an old fashioned nomenclature that is only employed for amino acids and sugars. The L- and D- nomenclature relies upon the absolute con?guration at the asymmetric center and not the direction at which the enantiomer rotates plane-polarized light. It is not probable to predict that in which way a molecule will rotate plane-polarized light and this can just only be found out via experimentation.