What connects Okazaki fragments during DNA replication?

During DNA replication, Okazaki fragments are short segments of DNA synthesized on the lagging strand. These fragments are initially created because DNA polymerase can only add nucleotides in a 5' to 3' direction. As a result, the lagging strand is synthesized discontinuously, leading to the formation of these fragments.

DNA ligase plays a critical role in connecting or "ligating" these Okazaki fragments together. After the fragments are synthesized, DNA ligase facilitates the formation of covalent bonds between the sugar-phosphate backbones of adjacent fragments, resulting in a continuous DNA strand. This ensures the integrity and continuity of the newly synthesized DNA.

Other proteins involved in the replication process include helicase, which unwinds the DNA double helix, and primase, which synthesizes short RNA primers necessary for DNA polymerase to start adding nucleotides. DNA polymerase itself is responsible for the actual synthesis of new DNA strands by adding nucleotides to a growing chain. However, none of these functions address the specific task of connecting the individual Okazaki fragments, which is exclusively the role of DNA ligase.