7.1  DNA Structure and Replication

big ninja

Essential Idea:

The structure of DNA is  

ideally suited to its function


  • DNA structure suggested a mechanism for DNA replication
  • DNA replication is carried out by a complex system of enzymes
  • DNA polymerase can only add nucleotides to the 3’ end of a primer
  • DNA replication is continuous on the leading strand and discontinuous on the lagging strand
  • Some regions of DNA do not code for proteins but have other important functions
  • Nucleosomes help to supercoil the DNA


  • Rosalind Franklin’s and Maurice Wilkins’ investigation of DNA structure by X-ray diffraction
  • Use of nucleotides containing dideoxyribonucleic acid to stop DNA replication in preparation of samples for base sequencing
  • Tandem repeats are used in DNA profiling


  • Analysis of results of the Hershey and Chase experiment providing evidence that DNA is the genetic material
  • Utilisation of molecular visualisation software to analyse the association between protein and DNA within the nucleosome