International Union of Pure and Applied Chemistry. See

Enzymes are classified in terms of the reactions which they catalyse and were formerly named by adding the suffix ase to the substrate or to the process of the reaction. In order to clarify the confusing nomenclature a system has been developed by the International Union of Biochemistry and the International Union of Pure and Applied Chemistry (see Enzyme Nomenclature , Elsevier, 1973). The enzymes are classified into divisions based on the type of reaction catalysed and the particular substrate. The suffix ase is retained and recommended trivial names and systematic names for classification are usually given when quoting a particular enzyme. Any one particular enzyme has a specific code number based upon the new classification. 

International Union of Pure and Applied Chemistry (see lUPAC). 

We have just seen that the three C5H12 isomers all incorporate pentane in their names and are differentiated by the prefixes n- iso , and neo. Extending this approach to alkanes beyond C5H12 fails because we run out of descriptive prefixes before all the isomers have unique names. As difficult as it would be to invent different names for the 18 constitutional isomers of CgHjg, for example, it would be even harder to remember which structure corresponded to which name. For this and other reasons, organic chemists have developed systematic ways to name compounds based on their structure. The most widely used approach is called the lUPAC rules lUPAC stands for the International Union of Pure and Applied Chemistry. (See the boxed essay. What s in a Name Organic Nomenclature,)... 

The names given above are based on those recommended by lUPAC - the International Union of Pure and Applied Chemistry (see Chap. 7). Though not very systematic, they reflect long established usage. The use of the endings -ite and -ate to indicate a lower and higher oxo-anion (e.g. nitrite, nitrate) parallels the use of -ous and -ic to indicate a lower and higher cation (Chap. 7). 

International Union of Pure and Applied Chemistry see lUPAC Interstellar Molecules, 14-6 to 8 Iodine see also Elements... 

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