Final- 16 Flashcards
Who discovered the double helix and when
April 1953
Watson and Crick
Who preformed the blender experiment
Hershey and Chase
What did the blender experiment show
DNA was the genetic material of the phage T2
What tagged the protein
Sulfur
What tagged the DNA
phosphorus
What did Erwin Chargaff do
Developed a series of rules based on a survey of DNA composition in organisms
- composition varies from one species to the next
- Number of A and T is equal to the number of C and G
What was published in 1953
a one page paper by Watson and Crick in Nature reporting their double helix model of DNA
Where replication begins
Origins of replication
What happens when the DNA strands separate
a replication bubble is created
What protein unwinds the strands of DNA
Helicase
Replication fork
Y shaped region where DNA strands are elongating
Single stranded binding proteins
Bind to and stabilize single stranded DNA. Stops DNA from sticking back together
Topoisomerase
Corrects overwinding ahead of replication forks by breaking , swiveling and rejoining DNA strands
RNA primer
Initial nucleotide strand, starting point for replication (5-10 nucleotides) at 3 prime end
Primase
Can start an RNA chain from scratch and adds RNA nucleotides one at a time using parental DNA as a template q
DNA polymerase
Add nucleotides to the 3 prime end (catylize the elongation of DNA at the replication fork)
What end is DNA added to
3 prime
Leading strand
Continuous. Moves towards replication fork
Lagging strand
Discontinuous. Moving away from the replication fork
Okazaki fragments
Laging strand synthesized as series of fragments `
DNA ligase
Joins Okazaki fragments together
What do limitations of DNA polymerase cause
No way to complete the 5 prime ends of the daughter DNA strands
Why do prokaryotic organisms not have a problem with their DNA stands not being completed at the 5 prime end
They have circular DNA molecules
Telomeres
Ends of eukaryotic chromosomal DNA molecules with special nucleotide sequences
