Essential Idea:
The structure of DNA is
ideally suited to its function
Understandings:
- 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
Applications:
- 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
Skills:
- 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