Enzymes play a major role in DNA replication because they catalyze several important stages of the entire process. DNA replication is one of the most essential mechanisms of a cell's function and therefore intensive research has been done to understand its processes.Enzymes play a major role in DNA replication because they catalyze several important stages of the entire process. DNA replication is one of the most essential mechanisms of a cell's function and therefore intensive research has been done to understand its processes.