7.1 DNA Structure and Replication

7.1 DNA Structure and Replication

1. DNA Structure

   • Nature of Science
     • Rosalind Franklin`s and Maurice Wilkins`investigation of DNA structure by X-ray diffraction
       • Rosalynd Franklin`s X-ray diffraction provided crucial evidence that DNA is a double helix
   • Nucleosomes help the supercoil of DNA
     • Some regions of DNA do not code for proteins but have other important functions
       • Some regions of DNA do not code for proteins
         • TOK
           • Tandem repeats are used in DNA profiling
           • Junk DNA
             • To what extent do the labels and categories used in the pursuit of knowledge affect the knowledge we obtain?
         • Regulators of gene expression
         • Introns
         • Telomeres
         • Genes for tRNAs
     • Histones
   • Hershey and Chase experiment
     • DNA is the genetic material

2. DNA Replication

   • DNA polymerase can only add nucleotides to the 3' end of a primer
     • Continuous on the leading strand
     • Discontinuous on the lagging strand
       • Okazaki fragments
   • Use of nucleotides containing dideoxyribonucleic acid to stop DNA replication in preparation of samples for base sequencing
   • Enzymes and Proteins
     • Helicase
     • DNA gyrase
     • DNA polymerase I and III
     • Ligase
     • DNA primase
     • Single strand binding proteins
   • Aim 6
     • Design models to illustrate ghe stages of DNA replication