INDUSTRY|chemistry
- eanantaiméir Reference Faomhadh an téarma seo mar chuid de Thionscadal Lex
- ga
- optical isomer | enantiomer
- en
- Definition one of a pair of molecular entities which are mirror images of each other and non-superposable Reference "IUPAC. Compendium of Chemical Terminology, 2nd ed. (the ""Gold Book""). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. http://goldbook.iupac.org/E02069.html [4.9.2009]"
- Comment An enantiomer can be named by the direction in which it rotates the plane of polarized light. If it rotates the light clockwise (as seen by a viewer towards whom the light is traveling), that enantiomer is labeled (+). Its mirror-image is labeled (−). The (+) and (−) isomers have also been termed d- and l-, respectively (for dextrorotatory and levorotatory). This labeling is easy to confuse with D- and L-.An optical isomer can be named by the spatial configuration of its atoms. The D/L system does this by relating the molecule to glyceraldehyde. Glyceraldehyde is chiral itself, and its two isomers are labeled D and L (typically typeset in small caps in published work).The D/L labeling is unrelated to (+)/(−); it does not indicate which enantiomer is dextrorotatory and which is levorotatory. Rather, it says that the compound's stereochemistry is related to that of the dextrorotatory or levorotatory enantiomer of glyceraldehyde—the dextrorotatory isomer of glyceraldehyde is, in fact, the D isomer.The D/L system remains in common use in certain areas of biochemistry, such as amino acid and carbohydrate chemistry, because it is convenient to have the same chiral label for all of the commonly occurring structures of a given type of structure in higher organisms. In the D/L system, they are nearly all consistent - naturally occurring amino acids are nearly all L, while naturally occurring carbohydrates are nearly all D.
- isomère optique
- fr
- Definition molécule différant par son activité optique Reference Lalanne Marcel,Gloss.de biochimie,Département de biochimie,Faculté de médecine,Université Laval,Québec,1998