How many DNA polymerases are in eukaryotes?
three DNA polymerases
Why does DNA polymerase have a 3 5 exonuclease activity?
The 3′–>5′ exonuclease activity intrinsic to several DNA polymerases plays a primary role in genetic stability; it acts as a first line of defense in correcting DNA polymerase errors. A mismatched basepair at the primer terminus is the preferred substrate for the exonuclease activity over a correct basepair.
Which DNA polymerase has 3 to 5 exonuclease activity?
Pol I then synthesizes DNA nucleotides in place of the RNA primer it had just removed. DNA polymerase I also has 3′ to 5′ and 5′ to 3′ exonuclease activity, which is used in editing and proofreading DNA for errors.
What does it mean to say that extension by DNA polymerase III?
Primase catalyzes the synthesis of RNA primer, then DNA polymerase III extends the leading strand, and the sliding clamp holds DNA polymerase in place during strand extension. DNA polymerase is unable to add DNA near the end of chromosome because it can’t synthesize DNA without a primer.
How many phosphodiester bonds are in DNA?
What happens during the formation of Okazaki fragments?
Okazaki fragments are initiated by creation of a new RNA primer by the primosome. To restart DNA synthesis, the DNA clamp loader releases the lagging strand from the sliding clamp, and then reattaches the clamp at the new RNA primer. Then DNA polymerase III can synthesize the segment of DNA.