Heterochirality

Part of speech: noun

Definitions

1. The condition of having molecules or structures with opposite handedness or chiral orientation; the presence of both left- and right-handed forms in a system; a state where mirror-image asymmetry is mixed within a chemical or biological context
2. A characteristic describing a mixture of enantiomers exhibiting both clockwise and counterclockwise molecular configurations; the coexistence of different chiral forms in compounds or organisms; a situation involving non-uniform spatial arrangement of asymmetric features
3. The quality of containing chiral entities of differing spatial asymmetry; occurrence of both dextrorotatory and levorotatory isomers in a sample; the simultaneous presence of distinct mirror-image molecular structures within a substance

Etymology: Heterochirality is a modern scientific coinage, built by combining two Greek-derived building blocks: "hetero-", from Greek "heteros" meaning "other" or "different", and "chirality", the term for handedness in molecules and objects. The second element comes from Greek "cheir", "hand", which also gave English words like "chiropractor" and "manual." Chirality itself was named in 1894 by Lord Kelvin, who used it for objects that cannot be superimposed on their mirror images, the way your left and right hands cannot be perfectly stacked on top of each other. Joining "hetero-" to "chirality" produces a word for the situation where a sample or organism contains a mixture of these mirror-image forms rather than only one. Chemists and biologists needed a single term for that mixture, so the compound was assembled from existing parts rather than inherited from older vocabulary.

Synonyms: chirality difference, molecular asymmetry

Antonyms: homochirality