Final answer:
DNA polymerase enzymes extend the range of DNA substrates during replication by synthesizing the leading and lagging strands of DNA in different ways.
Step-by-step explanation:
DNA polymerase enzymes play a key role in DNA replication by adding nucleotides one by one to the growing DNA chain. They can only extend the DNA strand in the 5' to 3' direction. However, at the replication fork, where the DNA double helix is anti-parallel, one strand is synthesized continuously (leading strand) while the other is synthesized in short fragments called Okazaki fragments (lagging strand). This allows the DNA polymerase to extend the range of substrates and ensure the complete replication of both strands.