Chiral refers to a molecule or object that exhibits chirality, meaning it cannot be superimposed on its mirror image. Chiral entities have a non-superimposable mirror image, often described as having “handedness.” This property arises when a molecule contains one or more asymmetric carbon centers or lacks a plane of symmetry or center of symmetry. Chirality is significant in chemistry and biology because it affects the molecule’s interactions with other molecules, including enzymes and receptors.
Chiral and achiral describe the symmetry properties of molecules. A chiral molecule has a non-superimposable mirror image, meaning it exhibits asymmetry in its spatial arrangement. For example, the amino acid alanine is chiral due to its asymmetric carbon atom, which gives rise to two enantiomers: L-alanine and D-alanine. In contrast, achiral molecules can be superimposed on their mirror images. An example is meso-tartaric acid, which despite having two chiral centers, possesses internal symmetry that makes it optically inactive.
Chiral compounds are molecules or objects that possess chirality, meaning they exhibit handedness and cannot be superimposed on their mirror images. This property is typically observed in molecules containing one or more asymmetric carbon atoms or lacking certain symmetry elements. Chirality plays a crucial role in various fields, including pharmacology, where the different spatial arrangements of chiral drugs can lead to distinct biological effects and interactions with receptors.
Achiral refers to molecules or objects that lack chirality and can be superimposed on their mirror images. These entities possess symmetry elements such as a plane of symmetry or a center of symmetry that divides them into halves that mirror each other. Achiral molecules do not exhibit handedness or asymmetry in their spatial arrangement. An example of an achiral molecule is benzene, which possesses a plane of symmetry passing through its center that divides it into two identical halves.