Example of enzyme specificity:

Ans. D. All of theseEnzymes are highly specific in their action as compared with chemical catalysts. Three types of enzyme specificities are well-recognized.(a) Stereospecificity: The enzymes act only on one isomer and therefore exhibit stereoisomerism. e.g., L-amino acid oxidase on L-amino acids; hexokinase on D-hexose (Note: isomerases do not exhibit stereospecificity).(b) Reaction specificity The same substrate can undergo different types of reactions, each catalyzed by a separate enzyme e.g., amino acids undergoing transamination, decarboxylation etc.(c) Substrate specifity This may be absolute, relative or broad e.g., urease, ligase, hexokinase.