Editing Stereoisomerism (section)

==Enantiomers==
{{Main|Chirality (chemistry)|Enantiomers}}
'''Enantiomers''', also known as '''optical isomers''', are two stereoisomers that are related to each other by a reflection: they are [[mirror image]]s of each other that are non-superposable. Human hands are a macroscopic analog of this. Every [[stereogenic center]] in one has the opposite configuration in the other. Two compounds that are enantiomers of each other have the same physical properties, except for the direction in which they rotate [[polarized light]] and how they interact with different enantiomers of other compounds. As a result, different enantiomers of a compound may have substantially different biological effects. Pure enantiomers also exhibit the phenomenon of [[optical activity]] and can be separated only with the use of a [[chirality (chemistry)|chiral]] agent. In nature, only one enantiomer of most chiral biological compounds, such as [[amino acid]]s (except [[glycine]], which is achiral), is present. Enantiomers differ by the direction they rotate polarized light: the amount of a chiral compound's optical rotation in the (+) direction is equal to the amount of its enantiomer's rotation in the (–) direction.