DNA ligase vs. DNA polymerase?

[studentdoctor08]

I know DNA polymerase is mainly used to replicate DNA, and DNA ligase is used mainly for DNA repair? But can DNA ligase be used for any other purposes besides repair as well, or is its sole function just to join DNA fragments together? What about other functions for DNA polymerase?

---

Members don't see this ad.

 

[Leonardo Noto]

I know DNA polymerase is mainly used to replicate DNA, and DNA ligase is used mainly for DNA repair? But can DNA ligase be used for any other purposes besides repair as well, or is its sole function just to join DNA fragments together? What about other functions for DNA polymerase?

You have part of the idea. DNA polymerase does add nucleotides to DNA chains (or RNA primers) and DNA ligase does link broken DNA chains back together. However, both DNA polymerase and DNA ligase are involved in both DNA replication and DNA repair. Find a good diagram of DNA replication (including Okazaki fragments) and DNA repair mechanisms--the actual enzymes involved differ somewhat in prokaryotes and eukaryotes, although the general process is fairly similar in both types of organisms for the most part.

Sorry that I haven't given you specifics but I haven't reviewed this stuff in detail in 10 years--what I told you is correct, however. Now go find the diagrams that I eluded to and understand them. Good luck on the MCAT!

Dr. Leonardo Noto
www.leonardonoto.com or follow me on Twitter @DrLeonardoNoto