DNA Replication: The Movie Report

Here is a link to the DNA Replication video that the group made:

https://www.youtube.com/watch?v=4fhPwZePSOU

Though we had read through the DNA Replication chapter in our textbook and even sat through multiple lectures with Mr. Wong about DNA Replication in both Eukaryotes and Prokaryotes, each member of the group learned more about DNA Replication through producing this video.

I think the most difficult concept to grasp from DNA Replication was the concept of the lagging strand. When I first came to class, I knew that DNA on the lagging strand was completed in fragments, but it didn't really understand why and how DNA Polymerase did this. Being forced to model the motion of the protein and track its path delivering and connecting nucleotides to the new strand of DNA after finding an RNA primer, I realized the how the protein's one way system of elongation worked. Because the strands are antiparallel and DNA Polymerase only works from the 5' to the 3' direction, the lagging strand must be broken into fragments to keep up with the splitting of the replication fork by helicase.

Furthermore, I had always wondered why the DNA strand couldn't just be split into two large molecules, the absolute 5' end of each molecule is primed, and then replication occurs, but only in one direction. Then, when I started putting together the fake DNA strands for the video and had to keep track of all the nucleotides and make sure the strand didn't double over or kink, I realized how impossible that split would be floating around in a cell's nucleus. The best way to counteract the kinking and twisting of the molecule would be to keep it together until the last possible moment, then split it and replicate the DNA. This is how cells do it, using replication bubbles instead of breaking up the entire strand of DNA.

I think my group made plenty of mistakes when creating our video, such as not using RNA and DNA Polymerase I to show how RNA primers on the new DNA molecule are removed, but I think that through this process, the entire group now has a mental representation of what DNA Replication must look like and has a concrete experience moving the proteins around. This will help us immensely when thinking critically about DNA problems, and being able to model the process in our minds will far outweigh other students' ability to memorize names and processes.