DNA Polymerase I and DNA Replication Process

How does DNA polymerase I add nucleotides during DNA replication?

Which direction does DNA polymerase I add nucleotides on single-stranded templates?

What is the difference in DNA synthesis between the leading and lagging strands?

Answer:

DNA polymerase I adds nucleotides at the 3' end of the primer after the removal of the RNA primer. This process takes place in a 5' to 3' direction on single-stranded templates. Replication occurs continuously on the leading strand and in fragments on the lagging strand.

During DNA replication, DNA polymerase I plays a crucial role in adding DNA nucleotides to the 3' end of the primer. This occurs after the RNA primer, which initiates DNA synthesis, is removed. The process of adding nucleotides by DNA polymerase I takes place in a 5' to 3' direction on single-stranded templates, ensuring the accurate replication of the DNA sequence.

In terms of DNA synthesis, the leading strand is replicated continuously in the direction of the replication fork. In contrast, the lagging strand is replicated discontinuously in short stretches known as Okazaki fragments. This difference arises because DNA polymerase can only add nucleotides in a 5' to 3' direction, necessitating the formation of multiple fragments on the lagging strand.

Once the DNA synthesis is completed on both the leading and lagging strands, the replicated DNA molecules move into separate cells during cell division, ensuring the accurate transfer of genetic information. Understanding the role of DNA polymerase I and the dynamics of DNA replication is essential for comprehending the intricate process of genetic duplication.