1. Which of the following enzymes is incorrectly paired with its function?

Question

a) DNA polymerase – catalyze the addition of dNTPs to a new DNA strand b) DNA ligase – produce RNA primers for Okazaki fragment formation c) DNA primase – produce RNA primer as a starting point for DNA synthesis d) DNA helicase – unwind DNA helix to separate strands x e) Telomerase – catalyze lengthening of telomeres in germ cells

Answer 1

Drew, the most incorrect association is e) where telomeres actually get shorter every time DNA is replicated as these are the ends of th DNA. These are lost because the primer does not start transcribing at the very end of DNA, rather at a initiation point. 

Answer 2

Drew,

 

While it is true that telomeres shorten with each cell division, it is also true that Telomerase repairs telomeres and participates in maintaining their length. Refer to an article published in Cell 2013 by Maria Blasco, the title is: Telomerase at the intersection of cancer and aging, log on to www.cell.com and you can read it.

 

 

In fact, DNA ligase joins the ends of DNA, it does not produce RNA primers for Okazaki fragments, it is involved in joining those fragments.  

 

DNA helicase unwinds supercoiled DNA.

 

DNA polymerase adds dNTPs and participates in elongation of newly synthesized DNA strand.

 

DNA primase participates in annealing of the primer to start DNA replication.

 

With that information, b is incorrect here.