What is the primary function of isomerases in biochemical reactions?

• A. Catalyzes the transfer of functional groups
• B. Catalyzes the rearrangement of bonds within a single molecule
• C. Catalyzes oxidation-reduction reactions
• D. Catalyzes hydrolytic cleavage reactions

Answer: (B)

Isomerases play a critical role in biochemical reactions by catalyzing the rearrangement of bonds within a single molecule, which allows for the conversion of one isomer into another. This function is essential in various metabolic pathways, as isomerization can influence the activity and properties of biomolecules, thereby affecting their biological functions.

For instance, isomerases are important in processes such as glycolysis, where glucose is converted into fructose-6-phosphate, and in the citric acid cycle where different isomers of sugar and organic acids are interconverted. This process may involve changing functional groups' positions or altering the connectivity of atoms within the molecule while keeping the molecular formula intact.

Understanding the specific role of isomerases highlights their importance in maintaining metabolic flexibility and ensuring that pathways are efficiently regulated and responded to cellular needs.