Which DNA polymerase has 5 to 3 exonuclease activity?
This exonuclease activity is called the proofreading or editing function of DNA polymerase I. Pol I also has a unique 5′ to 3′ exonuclease activity that is required for its DNA repair function.
What is the function of DNA polymerase 3 in DNA replication?
The main function of the third polymerase, Pol III, is duplication of the chromosomal DNA, while other DNA polymerases are involved mostly in DNA repair and translesion DNA synthesis.
Why does a new DNA strand elongates only in the 5 to 3 direction during DNA replication?
why does a new DNA strand elongates only in the 5′ to 3′ direction? DNA polymerase can only add nucleotides to the free 3′ end. relieving strain in the DNA ahead of the replication fork.
What is the major difference between the lagging and leading strand?
A leading strand is the strand which is synthesized in the 5′-3’direction while a lagging strand is the strand which is synthesized in the 3′-5′ direction. 2. The leading strand is synthesized continuously while a lagging strand is synthesized in fragments which are called Okazaki fragments.
What glues Okazaki fragments?
What is dna ligase for? It acts as a glue to put the Okazaki fragments back together.
Do we need primer in transcription?
One final difference lies in the capabilities of RNA polymerase versus DNA polymerase. RNA primers are needed to begin replication because DNA polymerase is unable to do it alone. DNA transcription does not have the same problem because RNA polymerase is capable of initiating RNA synthesis.
What is the difference between a primer and a promoter?
The promoter is on the original strand – it’s a short sequence on the strand of DNA to be copied that signals the beginning of the segment. The primer is a short piece of RNA that is in the environment of the cell that attaches near the promoter region.
How many primers are used in PCR?
Two primers