Question

Which enzymes show the greatest enzyme specificity ?
A) Nuclease
B) Trypsin
C) Sucrase
D) Pepsin

Answer 1

Enzymes are chemical substances which have a catalytic role in biological systems. These components are proteinaceous in nature and have binding region and catalytic region for their function.

Complete answer:
Enzymes are specific to their substrates, that is they are highly specific to the reaction they carry about and the reactant they act on, Nuclease are groups of Enzymes which can bring about the cleavage of nucleotides in the polynucleotide strand. They are off two types based on the region they cleave that is endonuclease- which can cleave nucleotides within the polynucleotide strand and exonuclease- which can cleave polynucleotide stands at its terminal ends. Nucleases are specific to a stretch of nucleotides, the number of nucleotides they are specific to vary. Trypsin is a serine protease which can bring about hydrolysis in proteins and results in amino acids. Pepsin cleave linkage at the C terminal side of the aromatic amino acids such as phenylalanine, leucine and so on, All the above Enzymes are considered to have moderate specificity. Sucrase is considered to have high specificity as they are specific not only to sucrose but also to its orientation in space.

Hence, the correct answer is option ‘C’.

Note: Based on the specificity Enzymes are grouped into major classes:

Absolute specificity: where the enzyme can catalyse only a particular type of reaction and they have their binding sites for the same, they will not have affinity to any other reactants.
Linkage specificity: here the Enzymes are specific to the type of bond they act on, they can either break or form a particular type of linkage between the molecules, for example Phosphodiesterase.
Group specificity: here Enzymes have catalytic sites which can bind to a particular functional group in a compound.
Stereochemical specificity: Enzymes will bind to specific forms of an isomer such as L form or D form of the same molecule.