Class 21

          Today in class we took a quiz on DNA and then discussed the DNA replication process. We worked on our DNA models, learning about the process of replication in DNA and the role of enzymes in this process. We learned that Helicase separates the double helix strands of DNA to be copied by unzipping the hydrogen bonds between the bases of the two strands. Primase binds a small stretch of RNA into an existing strand of DNA called the primer. DNA polymerase III attaches to the RNA primer and works in the 5' to 3' direction and adds the complementary nucleotides to form the new strand of DNA. DNA polymerase I replaces the RNA primers on the lagging strand with DNA nucleotides. DNA ligase joins the sugar-phosphate backbones of the Okasaki fragments to create a continuous strand of DNA. we went step by step in the process of enzymes in DNA replication. We then looked at our PGLO lab and saw that only one was glowing.