Replication is the process of accurately copying a DNA molecule, allowing genetic information to be transferred from one cell to another during division. This process is key to the growth, development and reproduction of organisms, as it provides each daughter cell with an identical set of genetic material. Replication occurs during the S-phase of the cell cycle in eukaryotes and before division in prokaryotes.
Replication begins with the unwinding of the DNA double helix, carried out by enzymes (helicases) that break the hydrogen bonds between nitrogenous bases. On each of the formed chains, a new complementary chain is synthesized with the participation of DNA polymerase. This process occurs in the direction of 5′ → 3′, which creates a leading and a delay circuit. To complete replication, other enzymes, such as ligase, combine DNA fragments to create a complete molecule.
Errors that occur during replication can be corrected by DNA repair mechanisms, however, some errors may remain, leading to mutations. Replication is important not only for life support, but also for research in genetics, medicine, and biotechnology, including the creation of genetically modified organisms and the development of new treatments for genetic diseases.