DNA Replication And The Cell Cycle Flashcards
When was the cell first discovered and by who
1665, through a microscope by Robert Hooke
Name the stages of mitosis
Interphase
Propase
Metaphase
Anaphase
Telophase
Who first identified mitosis
Fleming in 1882
What was found about interphase using radioactivity
Found molecules accumulated during the cell cycle, found DNA only increases during S phase
When did chick and Watson find the double helices
1953
What did meselson and stahl do in 1958
Experimental evidence for semi conservative replication using E.coli
-grew 15N e.coli- heavy isotope
-outcome only one band of 15N, got rid of the conservative idea
-cycle 2 got rid of disperse idea
What are the steps involved in DNA replication and the proteins involved
Initiation
Elongation
Termination
What is involved in initiation of DNA replication
Prokaryotes- bidirectional replication
Eukaryotes- bidirectional replication forms replication bubbles
What does a clamp loader do
Goes round the molecule and sticks on the DNA polymerase
-loading and holding on to the DNA strand
-the sliding clamp is loaded around DNA by a clamp loader
Outline helicase
The bases to be copied are in the middle of the sequence, so helicase unwinds the double- stranded DNA, using ATP
Outline topoisomerase
Helicase unwinding of DNA causes supercooling ahead of the replication form which neeed to be unwound by topisomerases
Outline single stranded binding protein
Prevents base-pairing until DNA polymerase arrives- binds to DNA, but DNA bases remain exposed. Stops DNA sticking together and forming a hairpin
What direction does synthesis occur
5’ to 3’ direction
Outline a replisome
DNA polymerase holoenzyme is an asymmetric dimmer that catalyses both leading and lagging strand synthesis
