How does DNA replicate, and what are the different enzymes involved?

DNA replicates through a semi-conservative process involving several enzymes.

During DNA replication, the double-stranded DNA molecule unwinds and separates into two strands. Each strand then serves as a template for the synthesis of a new complementary strand. The enzyme helicase unwinds the DNA double helix, while topoisomerase relieves the tension caused by the unwinding. Single-stranded binding proteins keep the two strands apart and prevent them from re-annealing.

The enzyme primase synthesizes a short RNA primer on each strand, which provides a starting point for DNA synthesis. DNA polymerase III then adds nucleotides to the 3’ end of the RNA primer, synthesizing a new DNA strand in the 5’ to 3’ direction. The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments called Okazaki fragments.

DNA polymerase I removes the RNA primers and replaces them with DNA, while DNA ligase seals the gaps between the Okazaki fragments. Finally, the two new DNA molecules are proofread and repaired by various enzymes to ensure their accuracy and integrity.

Overall, DNA replication is a complex process involving several enzymes that work together to ensure the faithful transmission of genetic information from one generation to the next.