chapter 10 - DNA Flashcards
-discovered bacterial transformation
-worked on 2 strains of bacteria
-living r strain transformed into s strain (which had a capsule) and mice died
griffith
-used radioisotopes to label the protein coat and DNA of the virus
-found that dna was the genetic material
hershey and chase
-analyzed dna and found it was made of phosphate, deoxyribose, and nitrogenous bases
-found a=t and c=g
chargoff
x-ray diffraction photo of dna
franklin
-published molecular structure of dna
-used chargoffs rules and franklins photo
-awarded nobel prize
watson and crick
dna structure
-2 strands
-phosphate, deoxyribose, nitrogenous base
-ATCG
rna structure
-1 strand
-phosphate, ribose, nitrogenous base
-AUCG
what is the structure of dna molecule
sugar phosphate backbone, double helix, nucleotide bases
helicase unwinds dna at the origin of replication
first step in dna replication
know that there are replication bubbles where proteins attach to dna at origin of replication and separate the strands. replication then proceeds in both directions creating bubbles. the parent strand opens up and daughter strands elongate on both sides of each bubble. all of these origins shorten the time needed for replication. then all the bubbles fuse make 2 complete daughter dna molecules
primase
adds rna primer to leading and lagging strands
adds dna nucleotides to both daughter strands using complimentary base pairing in the 5’ to 3’ direction (nucleotides added to 3’ end
dna polymerase
replace rna primer with dna nucleotides
dna polymerase
lagging strand must use this enzyme to join or glue the okazaki fragments together
dna ligase
corrects any mistakes during replication on daughter molecule aka the proof reading enzyme
dna polymerase
