What is the main function of ligase in DNA replication?

The primary function of ligase in DNA replication is to repair nicks on the lagging strand. During replication, DNA is synthesized in short segments known as Okazaki fragments on the lagging strand. Once these segments are formed, ligase comes into play to join these fragments together, sealing the gaps between them to create a continuous DNA strand. This is crucial for maintaining the integrity and stability of the DNA molecule during and after the replication process.

While other enzymes and processes are involved in adding complementary bases, elongating DNA strands, and breaking hydrogen bonds between the DNA strands, ligase specifically addresses the nicks and gaps that arise in the lagging strand, ensuring that the final replicated DNA molecule is complete and properly structured. This process is essential for accurate DNA replication and is a foundational aspect of molecular biology.