Question

1. What is DNA polymerase? Explain the roles of its various components in DNA replication.

2. What is RNA polymerase? Explain its role in transcription. How is RNA polymerase similar to and different from DNA polymerase?

Answer 1

Ans1. DNA polymerase is one of the most important molecule or enzyme in DNA replication which synthesis DNA. This enzyme tends to add nucleotide in the growing DNA template one by one. It can only extends the pre existing DNA strand and cant initiate the synthesis of new template.

DNA Polymerase's structure is of conserved nature. This enzyme can be divided in domains which. Shape of molecule can referred as righy hand palm thumb and finger domain.

function of palm domain-

catalye the transfer of phosphoryl groups in phosphoryl transfer rreactiom.

function of thumb domain -

Helps in processivity, translocation and positioning of DNA.

Function of finger domain -

Binds nucleoside triphosphates with template bas

Ans2. RNA polymerase is an enzyme that involved in addition of nucleotides to mRNA (messenger RNA) from DNA during the process of transcription. RNA polymerase is the main enzyme in the transcription process the addition of nucleotide to mRNA forms the polypeptide containing amino acid encoding codons which later are being converted to polypeptide of protein in the process of translation.

Both of the DNA and RNA polymerase synthesize genetic materials. This is the main similarity between DNA and RNA polymerase.

Differenes between DNA and RNA polymerase:-

1. DNA polymerase works in DNA replication while RNA polymerase helps in transcription.

2. RNA polymerase does not require primer to initiate the process unlike DNA polymerase.

3. DNA polymerase synthesize DNA strand while RNA polymerase synthesize mRNA strand.

4. RNA polymerase can initiate the synthesis of a new strand while DNA polymerase can't.

5. RNA polymerase is 10 times slower than DNA polymerase.