What do Okazaki fragments represent during DNA replication?

Okazaki fragments are short sequences of newly synthesized DNA that are generated during the replication of the lagging strand in DNA. During DNA replication, the two strands of the double helix are separated, with one being synthesized continuously in the direction of the replication fork (the leading strand) and the other being synthesized in short segments away from the fork (the lagging strand).

As the DNA helicase unwinds the double helix, the lagging strand cannot be synthesized continuously because its template strand runs in the opposite direction to the movement of the DNA polymerase. Instead, it is synthesized in segments—these segments are called Okazaki fragments. Each fragment is synthesized in the 5’ to 3’ direction, but because they are formed in short sequences, they are later joined together by the enzyme DNA ligase to create a continuous strand.

This understanding highlights the essential mechanism by which DNA replication achieves the necessary fidelity and structure, ensuring that the genetic material is accurately copied and passed on during cell division.