DNA structure and replication

Topic 7.1

Essential idea: The structure of DNA is ideally suited to its function.


7.1.U1 Nucleosomes help to supercoil the DNA

The figure below illustrates the components of a nucleosome which help to supercoil chromosomes and help to regulate transcription.

Place mouse pointer on Figure 2 to show structure of nucleosomes.

nucleosome link nucleosome animation
Trophic levels in a food web

7.1.U2 DNA structure suggested a mechanism for DNA replication

Diagram release of thyroxing from thyrooid

7.1.U3 DNA polymerase is can only add nucleotides into the 3' end of a primer

DNA polymerase and primer

7.1.U4 DNA replication is continuous on the leading strand and discontinuous on the lagging strand

DNA polymerase and continuous strands

7.1.U5 DNA replication is carried out by a complex system of enzymes

Enzymes used in DNA replication

DNA replication explained

DNA replication explained

7.1.U6 Some regions of DNA do not code for proteins that have other important functions

Functions of noncoding regions in DNA


7.1.A1 Rosalyn Franklin's and Maurice Wilkins' investigation of DNA structure by x-ray diffraction

DNA xray diffraction pattern and dimension calculations

7.1.A2 Use of nucleotides containing dideoxyribonucleic acid to stop DNA replication in preparation of samples for base sequencing

Base sequencing with dideoxyribonucleic acid

7.1.A3 Tandem repeats are used in DNA profiling

DNA profiling involves the use of gel electrophoresis of DNA.

What are microsatellites and short tandem repeats?

Microsatellites are STRs

How short tandem repeats are used in DNA profiling?

DNA profiling using microsatellites


7.1.S1 Analysis of results of the Hershey and Chase experiment providing evidence that DNA is the genetic material

Phage grown on 35S radioactive medium
Phage grown on 32P radioactive medium
Conclusion Hershey Chase experiments

7.1.S2 Utilization of molecular visualization software to analyze the association between protein and DNA within a nucleosome

Goto Visualization software website
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