Enantiomers have different physical arrangement of atoms. They play a very important role in biology.

But, why do enantiomers have different biological activities?

Recognition of chiral drugs by specific drug receptors is explained by a three-point interaction of the drug with the receptor site, as proposed by Easson and Stedman. The difference between the interaction of the two enantiomers of a chiral drug with its receptor is illustrated below.

Source: https://www.khanacademy.org/test-prep/mcat/chemical-processes/stereochemistry/a/chiral-drugs

Enantiomers have different physical arrangement of atoms. This difference plays a crucial role in biology.

But, why do enantiomers have different biological activities?

Recognition of chiral drugs by specific drug receptors is explained by a three-point interaction of the drug with the receptor site, as proposed by Easson and Stedman. The difference between the interaction of the two enantiomers of a chiral drug with its receptor is illustrated below.

Source: https://www.khanacademy.org/test-prep/mcat/chemical-processes/stereochemistry/a/chiral-drugs