Question

1. List all the reagents (chemicals) and enzymes required to synthesize DNA. Describe how DNA polymerase works. What does DNA polymerase require in order to polymerize DNA?

Answer 1

Some of the agents/chemicals required for DNA synthesis are as:-

Parental DNA, RNA primers, DNA polymerase enzyme, free nucleotides, enzyme helicase, single strand binding proteins, RNA Primase, DNA ligase.

Working of DNA Polymerase:- once the DNA is unwinded by the enzyme helicase then DNA polymerase starts adding nueotides to the 3' end of the newly formed strand elongating in the 5' to 3' direction. The DNA polymerase enzyme cannot initiate the addition of nucleotides by its own but it needs a free 3'-OH group of an existing nucleotide which is provided to it by the primer already formed by the RNA primase. Once the DNA synthesis is finished then DNA polymerase starts the proofreading activity and repairs the mistakes done during copying of DNA.

So from this it is clear that DNA polymerase require a free 3'-OH group of a nucleotide which is made available to the polymerase by the primer synthesized by primase.