What happens at a DNA replication fork during replication?

Polymerases are enzymes that utilise a single strand of DNA to synthesize new DNA; however, since DNA is double stranded, they must first separate from one another in order for the polymerases to begin replicating DNA.

The replication fork, which is formed by specialized enzymes called helicases that break hydrogen bonds between strands and unwind the DNA helix, is where this strand separation occurs.

Helper proteins help the helicase maintain the separation of the strands so that polymerases can attach and initiate the replication process.

At a DNA replication fork during replication, the double-stranded DNA molecule is unwound by helicase enzymes. Single-stranded binding proteins stabilize the separated strands. DNA polymerase enzymes then add complementary nucleotides to each of the original strands, synthesizing new daughter strands. This process occurs in a continuous manner on one strand (leading strand) and discontinuously in short fragments called Okazaki fragments on the other strand (lagging strand). RNA primers are initially synthesized by primase to provide a starting point for DNA polymerase. The RNA primers are later removed, and the gaps are filled in by DNA polymerase and sealed by DNA ligase, resulting in two identical daughter DNA molecules.