How does DNA replication occur in cells?

DNA replication occurs when a cell divides, with enzymes helping to unzip the DNA and build new strands.

DNA replication is a vital process that occurs in all living organisms as it is essential for biological inheritance. This process takes place in the nucleus of the cell. The first step in DNA replication is the separation of the two strands of the DNA double helix. This separation is carried out by an enzyme called DNA helicase. This enzyme breaks the hydrogen bonds holding the base pairs of DNA together, causing the DNA to 'unzip'.

Once the DNA is unzipped, another enzyme called DNA polymerase comes into play. This enzyme moves along the unzipped strands of DNA, reading the existing strands and synthesising new strands that are complementary to the existing ones. This is done by matching the bases on the existing strand (adenine with thymine, and cytosine with guanine) to create the new strands.

The replication process is semi-conservative, meaning that each of the two new DNA molecules contains one old strand and one new strand. This ensures that the new DNA molecules are identical to the original.

The process of DNA replication is highly accurate due to the 'proofreading' function of DNA polymerase. This enzyme checks the newly synthesised DNA strand for errors and corrects them. This ensures that the DNA is copied accurately, which is crucial for the proper functioning of the organism.

In summary, DNA replication is a complex but highly efficient process that ensures the accurate transmission of genetic information from one generation to the next. It involves several enzymes, including DNA helicase and DNA polymerase, which work together to unzip the DNA, synthesise new strands, and proofread the new DNA to ensure accuracy.