Final answer:
Enantiomers are stereoisomers that are non-superimposable mirror images of each other. They are recognized by inverting the configuration at each chiral center of a molecule. They also interact differently with plane polarized light, with one enantiomer rotating light to the right (dextrorotary) and the other to the left (levorotary).
Step-by-step explanation:
Understanding Enantiomers
Enantiomers are a type of stereoisomer that are non-superimposable mirror images of each other. This is particularly evident in organic molecules that have a chiral center, typically a carbon atom with four different groups attached to it. For instance, D-glucose and L-glucose are monosaccharides that are enantiomers, as are D-alanine and L-alanine. Enantiomers are significant in biochemistry since biological systems are often sensitive to the chirality of molecules, with enzymes and receptors typically binding to only one enantiomeric form.
When looking for an enantiomer of a given compound, the key is to find or draw a molecule that is a mirror image of the original but cannot be superimposed onto it. This involves flipping the configuration at each chiral center. For example, if the student is asked to identify the enantiomer of a molecule, they should look at the configuration of atoms around its chiral centers and find the structure that inverts these configurations. Referencing figures that illustrate examples of enantiomers, such as those of alanine or glucose, can help visualize this concept.
Moreover, the interaction of enantiomers with plane polarized light illustrates their chiral nature. While not all enantiomers rotate plane polarized light in the same direction, a given pair of enantiomers will always rotate light in opposite directions, with one enantiomer causing dextrorotary (right) rotation, denoted by d or D, and the other levorotary (left) rotation, denoted by l or L.