Chapter 6, Problem 20P

a.

Do any strands of nucleic acid exist in nature in which part of the strand is DNA and part is RNA? If so, describe when such strands of nucleic acid are synthesized. Is the RNA component at the 5′ end or at the 3′ end?

b.

RNA primers in Okazaki fragments are usually very short, less than 10 nucleotides and sometimes as short at 2 nucleotides in length. What does this fact tell you about the processivity of the primase enzyme—that is, the relative ability of the enzyme to continue polymerization as opposed to dissociating from the template and from the molecule being synthesized? Which enzyme is likely to have a greater processivity, primase or DNA polymerase III?