Describe the term D- and L-configuration used for amino acids with examples.

Explanation

The sugars are divided into two families : the D-family and L-family which have definite configurations. These configurations are represented with respect to glyceraldehyde as the standard. The glyceraldehyde may be presented by two forms as:

`D-(+)-" Glyceraldehyde "L-(-)-" Glyceraldehyde"`
The D - configuration has `-OH` attached to the carbon adjacent to `-CH_(2)OH` on right white L - configuration has `-OH` attached to the carbon adjacent to `-CH_(2)OH` on left. The sugars are called D - or L - depending upon whether the configuration of the molecule is related to D - glyceraldehyde or L - glyceraldehyde. It has been found that all naturally occurring sugars belong to D - series e.g., D - glucose, D - ribose and D - fructose.