Question

Describe the process of DNA replication; include the following terms: antiparallel structure, Topoisomerase, DNA polymerase I and III, leading strand, lagging strand, Okazaki fragments, DNA ligase, RNA primer, primase, helicase, single-strand binding proteins

a. first on each strand

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b. then on the lagging strand

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c. then on the leading strand

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and what are the differences between what happen between the leading and the lagging?

Answer 1

sDNA replication is the process by which there would be production of identical DNA replicas. These would be same as the original molecule. This is a process that takes place in every living organism, and would be the basis of inheritance. This is a distinctive property that a cell would posses making DNA replication the essential life process.

In replication, both the strands would be separated. Both these strands would be serving as templates such that there would be production of a counterpart, labelling this process as semi conservative DNA replication. There are mechanisms that serve for checking errors.

The process of replication would start at sites referred to as ori sites or origin of replication. In this, the replications forks would be having bi directional origin. DNA synthesis would e initiated and would continue.

Also, DNA polymerase would be synthesising newer strands as these would be adding nucleotides. DNA replication would take place in the s phase of interphase. DNA pol would be adding nucleotides at the 3’ end of the current chain. This would be done by formation of phophodiester bonds.

Initiation of replication would take place at the origins. The protein is DnaA in e.coli. Elongation takes place in a 5’ to 3’ direction, where, a free hydroxyl group would be required. The leading strand would be synthesised in a continous form, whereas, the lagging strand extends using Okazaki fragments.t this is because primate would be adding rna primers on the template strand, and on the lagging strand, this is continuously done.

The DNA pol III would carry out extension, whereas, exonuclease activity would be carried out using DNA pol I. As rna would be removed, the nick gets translated, which is covered using DNA ligament enzyme. Replication fork is the structure that helps in DNA synthesis.