DNA replication Flashcards
What experiment did Griffith carry out to reveal that DNA as the hereditary material?
One living strain of bacteria (streptococcus pneumoniae) could be genetically transformed by dead material from another strain.
Another experiment that was carried out by Alfre and Martha revealed that DNA as the hereditary material?
Bacteriophage T2 virus was used to determine whether DNA or protein is the genetic material
What was the final experiment that was carried out to reveal DNA as the hereditary material?
Experiment that used 35C radiolabelled protein and 32P labelled DNA by Alfred and Martha
What is the structure of DNA?
Double stranded helix, with 10 nucleotides in each full turn and a diameter of 2nm, suggesting that sugar phosphate backbone of each strand is on the outside.
What bases are purines?
A and G
What bases are Pyrimidines?
T and C
What is semiconservative replication?
it would produce molecules with both old and new DNA, but each molecule would contain one complete old strand and one new one
What evidence backs up semi-conservative?
The Meselon-stahl experiment provided evidence to support the semi-conservative model of DNA replication
Where does DNA replication initiates?
Origin of replication
The role of DNA polymerase?
DNA polymerase binds to the template strand. It requires a primer, a short started strand-usually RNA.
The primer is complementary to the DNA template and is synthesized by a primase.
DNA polymerase then addes nucleotides to the 3’end until that section is complete and the primer is degraded.
What is the role of DNA helicase
Uses ATP hydrolysis to open the double stranded DNA, to expose the template strands for DNA polymerase.
Leading and lagging strand look at the diagram from workshop
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