Question: 117. Name the class of enzyme that usually catalyze the following reaction:
\mathrm{S}-\mathrm{G}+\mathrm{S}^{\#} \rightarrow \mathrm{~S}+\mathrm{S}^{\#}-\mathrm{G}Where, \mathrm{G} \rightarrow a group other than hydrogen
S → a substrate
\mathrm{S}^{\#} \rightarrow another substrate
(1) Hydrolase
(2) Lyase
(3) Transferase
(4) Ligase
Answer: Option (3)
Explanation:
In the given reaction, a functional group \mathrm{G} is transferred from one substrate to another.
The group \mathrm{G} is originally attached to substrate \mathrm{S} forming \mathrm{S}-\mathrm{G}, and after the reaction it is transferred to another substrate \mathrm{S}^{\#} forming \mathrm{S}^{\#}-\mathrm{G}.
Thus, the reaction involves transfer of a chemical group between two substrates without breaking the molecule by hydrolysis.
Enzymes that catalyze the transfer of functional groups such as methyl, amino, phosphate, or glycosyl groups from one molecule to another are classified as transferases.
Therefore, the correct answer is transferase.