Inconsistencies in some common terms and notations in enzymology: Textbook examples and suggestions.

A number of terms have been defined and inconsistently used across various texts in enzymology which may attract the attention of undergraduate students and instructors. At some places, inconsistent use results in confusions as well as leads to the misuse of these terms. Although it is difficult to resolve such inconsistencies, attempts have constantly been made by international regulatory forums such as International Union of Biochemistry and Molecular Biology (IUBMB) and other similar organizations to abolish the inconsistencies. This article highlights some of the most commonly occurring confusing and inconsistent terms in enzymology. We have gathered shreds of evidences and provide here possible suggestions and caution for readers and instructors, so that mistakes can be minimized and possible guidelines can be prepared for their usage. A few inconsistencies observed and discussed here include different notations of activation energy, differences in terms uncompetitive and noncompetitive in enzyme inhibition, classification of cofactors and definitions of their sub-types, and confusing usage of the enzyme-inhibitor dissociation constant. Besides this, we have also highlighted the inconsistencies in the enzyme nomenclature. © 2018 International Union of Biochemistry and Molecular Biology, 47(2): 140-144, 2019.