Dna history
The history of DNA structure discovery(sec.4.1):
1869- Johan miescher
•studies the nuclei of white blood cells(isolated th material using HCL and digestive proteins
•Named the substance nulclein and also found the material was rich in nitrogen and phosphorus.
1919-Pheobus levene
•Discovered that DNA was made of chains of nucleotides *see nucleotide structure*
1920 DNAvsRNA * see chart
•Thought that 4 nucleotides were connected in the same repeated pattern
•protein gas 20 amino acids which could be combined in many combinations
1928- Frederick Griffith
•studied tho starins of pnuemococccus bacteria
•Rough strain-nonvirulent
-Injection into mouse did not result in death
•smooth strain=virulent(poisonous)
-injection caused death
•conclusion; some factor from the dead, virulent smooth strain transformed rthe living non-virulent rough strain.
-Non virulent rough strain picked up DNA becoming virulent.
1930-joachim hammerling
*see image in notebook*
•nucleus controls phenotypic properties of algae
Avefry continued Griffiths work:
•purified chemicals from the heat-killed virulent bacteria, including DNA
•transformed non-Virulent bacteria with each chemical into viruent
•only DNA resulted in death of the mouse
•Conclusion: transforming agent is DNA, thus DNA carries information to change living cell.
1944-Avey, McCarty, and MacLeod
•Continued Griffiths work with pnemococcus see notebook*
1940s-Joshua Lederberg
•demonstrated bacterial conjugation
-bacteria can exchange DNA
•Baccteria have no nucleus or chromosomes.
1940s- Edwin Chargaff
•For all organisms A=T and G=C (chargaff’s rule)
•Organsisms with more Gs and Cs tend to be more complex (3 h-bonds)
1952-Hersey &chase
•Conducted experiments to show definitive data to show DNA is the hereditary material.
•Bacteriophage used to infect bacteria.
•what they knew:
-virus are composed of DNA and protein
-virus infection reprograms a host cell to produce more virus.
1869- Johan miescher
•studies the nuclei of white blood cells(isolated th material using HCL and digestive proteins
•Named the substance nulclein and also found the material was rich in nitrogen and phosphorus.
1919-Pheobus levene
•Discovered that DNA was made of chains of nucleotides *see nucleotide structure*
1920 DNAvsRNA * see chart
•Thought that 4 nucleotides were connected in the same repeated pattern
•protein gas 20 amino acids which could be combined in many combinations
1928- Frederick Griffith
•studied tho starins of pnuemococccus bacteria
•Rough strain-nonvirulent
-Injection into mouse did not result in death
•smooth strain=virulent(poisonous)
-injection caused death
•conclusion; some factor from the dead, virulent smooth strain transformed rthe living non-virulent rough strain.
-Non virulent rough strain picked up DNA becoming virulent.
1930-joachim hammerling
*see image in notebook*
•nucleus controls phenotypic properties of algae
Avefry continued Griffiths work:
•purified chemicals from the heat-killed virulent bacteria, including DNA
•transformed non-Virulent bacteria with each chemical into viruent
•only DNA resulted in death of the mouse
•Conclusion: transforming agent is DNA, thus DNA carries information to change living cell.
1944-Avey, McCarty, and MacLeod
•Continued Griffiths work with pnemococcus see notebook*
1940s-Joshua Lederberg
•demonstrated bacterial conjugation
-bacteria can exchange DNA
•Baccteria have no nucleus or chromosomes.
1940s- Edwin Chargaff
•For all organisms A=T and G=C (chargaff’s rule)
•Organsisms with more Gs and Cs tend to be more complex (3 h-bonds)
1952-Hersey &chase
•Conducted experiments to show definitive data to show DNA is the hereditary material.
•Bacteriophage used to infect bacteria.
•what they knew:
-virus are composed of DNA and protein
-virus infection reprograms a host cell to produce more virus.