Isomerases are a type of enzyme that facilitate the rearrangement of molecular structures within a compound. They help convert one isomer into another, which can change the chemical properties and biological activity of the molecule. This process is essential in various metabolic pathways, allowing cells to adapt and utilize different forms of nutrients. These enzymes play a crucial role in processes such as glycolysis and DNA replication. By enabling the conversion of substrates into their isomeric forms, isomerases contribute to the overall efficiency and regulation of biochemical reactions in living organisms.