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

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

DNA replication is the process by which a cell duplicates its DNA before cell division. This ensures that each daughter cell receives a complete set of genetic information. The process is semi-conservative, meaning that each new DNA molecule consists of one original strand and one newly synthesized strand.

The first step in DNA replication is the unwinding of the double helix by the enzyme helicase. This creates a replication fork, where the two strands of DNA are separated. Single-stranded binding proteins then stabilize the separated strands to prevent them from re-forming the double helix.

Next, the enzyme primase synthesizes a short RNA primer on each strand, which provides a starting point for DNA synthesis. The enzyme DNA polymerase III then adds nucleotides to the growing DNA strand, using the original strand as a template.

As the DNA strands are antiparallel, the two strands are replicated differently. The leading strand is synthesized continuously in the 5' to 3' direction, while the lagging strand is synthesized in short fragments called Okazaki fragments, which are later joined by the enzyme DNA ligase.

Finally, the RNA primers are removed by the enzyme DNA polymerase I and replaced with DNA nucleotides. The result is two identical DNA molecules, each consisting of one original strand and one newly synthesized strand.

In summary, DNA replication is a complex process involving multiple enzymes, including helicase, primase, DNA polymerase III, DNA ligase, and DNA polymerase I. The process is semi-conservative, ensuring that each daughter cell receives a complete set of genetic information.