How are RNA polymerases different than DNA polymerases?

The main difference between DNA and RNA polymerase is that DNA polymerase produces a double-stranded DNA molecule during polymerization whereas RNA polymerase produces a single-stranded RNA molecule during transcription.

What can RNA do that DNA Cannot?

DNA cannot catalyze its own synthesis while RNA can. The pairing of bases in DNA including A-T(Adenine-Thymine) and G-C(Guanine-Cytosine)is different to that of RNA including A-U(Adenine-Uracil) and G-C(Guanine-Cytosine).

Why is RNA polymerase used instead of DNA polymerase?

The reason for exclusive RNA primers in cellular DNA replication is the non availability of DNA primers. The RNA primers complimentary to cellular DNA are easily synthesized by DNA Primase enzyme which is nothing but RNA polymerase just like mRNA ( RNA synthesis by RNA primase doesn’t need primer).

Can RNA polymerase function without unwinding the DNA?

In contrast to DNA polymerase, RNAP includes helicase activity, therefore no separate enzyme is needed to unwind DNA.

Can RNA polymerases proofread?

All nucleic acid polymerases insert incorrect nucleotides during chain elongation. This high rate of mutation comes from the lack of proofreading ability in RNA polymerases. These enzymes make mistakes, but they can’t correct them.

Why Cannot a DNA polymerase start polymerization de novo?

DNA polymerase cannot initiate new strands of nucleic acid synthesis because it can only add a nucleotide onto a pre-existing 3′-OH…….. DNA polymerase cannot synthesize new DNA without a pre-exisiting 3′-OH. Thus,DNA replication requires an RNA primer to initiate strand formation.

How does the role of RNA polymerase in transcription differ from that of DNA polymerase in DNA replication?

The DNA is a double-stranded molecule, while the RNA is single-stranded- formed from the DNA during transcription. Based on that, another difference between both is that the DNA polymerase manufacture double-stranded DNA while the RNA polymerase manufacture a single-stranded RNA.

Why do you think it is more important for DNA polymerase than for RNA polymerase to proofread?

It synthesizes single-stranded RNA during the transcription process. It required a holoenzyme to function properly, although does not have a proofreading activity. Hence the error rate of the RNA polymerase is much higher than the DNA polymerase.

What is RNA polymerase function?

RNA polymerase is an enzyme that is responsible for copying a DNA sequence into an RNA sequence, duyring the process of transcription. For instance, bacteria contain a single type of RNA polymerase, while eukaryotes (multicellular organisms and yeasts) contain three distinct types.