( iv ) Xanthoprotic test
Enzymes
Enzymes constitute a group of complex proteinoid compounds , produced by living organisms which catalyse the chlemical reaction .
Non-proteinous components enhance the activity of certain enzymes and are known as co-enzymes . These include metal ions like Mn 2 + , Mg 2 + , K + , Na + , Zn 2 + , Co 2 + etc ., heterocyclic ring systems ( pyrrole , purine , pyridine , etc .), a sugar residue , phosphoric acid residue of vitamins like thiamine , riboflavin etc .
Endoenzyme acts in the same cell in which it is synthesised , while exoenzyme acts outside the cell in which it is synthesised .
Nomenclature
They are usually named by adding the suffix „ ase ‟ to the root name of the substrate e . g ., urease , maltase , diastase , invertase , etc .
Oxidative Enzymes
They catalyse oxidation-reduction reaction and are mostly conjugated proteins .