There are chiral pharmaceuticals whose curative properties are due to just one of the two handed forms and others where both enantiomers are effective but one is toxic or harmful in some way. One such drug is D-penicillamine. An enantiomer is one of the pair of molecular species that are mirror images of each other and not superposable. Thus enantiomers are mirror-image stereoisomers. Stereoisomers not related as mirror images are diastereomers.
Dextrorotatory asparagine has a sweet taste, whereas levorotatory asparagine is tasteless.