Final answer:
In double-strand break repair, DNA polymerase synthesizes new DNA to fill in the gap left after the break. It works in conjunction with other enzymes like helicase, topoisomerase, single-strand binding proteins, primase, and DNA ligase to ensure accurate repair and maintain genetic integrity.
Step-by-step explanation:
In double-strand break repair, DNA polymerase synthesizes new DNA to fill in the gap left after the break has been processed. The repair process involves several steps and enzymes. Helicase unwinds the DNA at the origin of replication. Topoisomerase breaks and reforms the DNA's phosphate backbone ahead of the replication fork to relieve the tension caused by supercoiling. Single-strand binding proteins stabilize the unwound DNA strands to prevent them from re-annealing prematurely. Primase synthesizes an RNA primer that is necessary for DNA polymerase to begin the replication process. On the leading strand, replication is continuous, while on the lagging strand, it is discontinuous, resulting in short DNA segments known as Okazaki fragments. DNA polymerase I replaces the RNA primers with DNA, and DNA ligase seals the nicks to complete the replication process. When a double-strand break occurs, cells use a similar mechanism to repair the damage, ensuring the maintenance of genetic integrity, which is crucial for the survival of species.