Flashcards in DNA replication - lecture 2 Deck (13)
What did Arthur Kornberg discover and when?
1959 - discovering the mechanism for biological synthesis of DNA
What is the difference between eukaryote and prokaryote replication?
Eukaryote - multiple site of origin, speeds up replication slightly
Prokaryote - one site of replication
Does DNA replicate uni or bi-directionally?
DNA synthesis can occur both uni- directionally and bi - directionally.
To replicate bi- directionally , a replication fork must occur .
How does the leading strand replicate?
Continuously , in 5' to 3' direction
How does the lagging strand replicate?
Discontinuously. Still 5' to 3' .
RNA primate adds an RNA primer to start synthesis.
Polymerase can add Okazaki fragments , after the RNA is added. DNA polymerase 3 lays down new DNA.
Finally DNA ligase joins the fragments together.
What does dNTP stand for? what does it do?
deoxynucleotide triphosphate. This is the substrate used to extend the DNA sequence .
What type of nucleic acid are the primers?
What are the 6 common rules of DNA replication?
- Semi - conservatief
- Starts at 'ori'
- Can be uni or bidirectional
- Semi - discontinuous
- synthesis 5' to 3'
- RNA primers required
prevents torsion by DNA breaks
Singel strand binding proteins
prevent reannealing of single strands
stabilises DNA polymerase
RNA primer synthesis