DNA Properties and Experiments Flashcards
What are the properties of genetic material
carries information
capable of being copied
is capable of undergoing change
Describe the Griffith experiment
Using two strains of a bacteria, R cells and S cells that are either living or heat killed
Living S cells - mouse dies
Living R cells - mouse lives
Heat killed S cells - mouse lives
Living R cells and heat killed S cells - mouse dies
proves transfer of genetic material
Describe Avery, MacLeod, and McCarty experiment
To understand transforming principle of DNA
Takes RNA, DNA, protein, and a polysaccharide from Smooth cells
adds rough cells
only DNA transformed rough cells to smooth cells
Describe Hershey and Chase experiment
Take radioactive S-35 and mix with bacteriophage and infect the bacterial cell
Blend the virus and bacteria mixture to knock off phages
Centrifuge a sample
find a pellet of bacterial cells at the bottom without radioactivity
Tells us that radioactive bacteriophage does not make the bacterial cell radioactive and the phage did not enter cell
What did Watson and Crick find?
The DNA Structure of purines and pyrimidines and how they hydrogen bond
semiconservative model of replication
What is the semiconservative model
when a double helix replicates, each daughter molecule will have one old strand and one newly made strand
Who supported semiconservative model by experiment
Matthew Meselson and Franklin Stahl
Describe Meselson and Stahl experiment
Bacteria cultured in N-15 medium
Bacteria transferred to N-14 medium
Sample centrifuged for 20 min (1 replication) and found one band of pure DNA suspended in the tube
Sample centrifuged for 20 min (after first replication) and found 2 bands of DNA with one less dense than the other
