During DNA replication, what is the primary purpose of the leading strand?

The primary purpose of the leading strand during DNA replication is to be synthesized continuously towards the replication fork. This occurs because DNA polymerase, the enzyme responsible for synthesizing new DNA strands, can only add nucleotides in the 5’ to 3’ direction. As the double helix unwinds at the replication fork, the leading strand is exposed in a way that allows for continuous synthesis in the same direction as the fork is progressing. This efficient, uninterrupted process contrasts with the synthesis of the lagging strand, which occurs in short fragments due to its orientation relative to the fork. Understanding this distinction is important for grasping how DNA replication ensures that both strands of the helix are replicated accurately and efficiently.