BIOL 1020 Chapter Notes - Chapter 16: Enterobacteria Phage T2, Maurice Wilkins, Linus Pauling

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 1020
• Professor: Joy Stacey

Document Summary

Frederick griffith in 1928: he studied streptococcus pneumoniae, a bacterium that causes pneumonia in mammals. One strain, the r strain, was harmless. The other strain, the s strain, was pathogenic: griffith mixed heat-killed s strain with live r strain bacteria and injected this into a mouse. Macleod announced that the transforming substance was dna: still, many biologists were skeptical. Proteins were considered better candidates for the genetic material. To replicate, a virus infects a host cell and takes over the cell"s. They grew one batch of t2 phage in the presence of radioactive sulfur, marking the proteins but not dna. They grew another batch in the presence of radioactive phosphorus, marking the dna but not proteins. They allowed each batch to infect separate e. coli cultures. Shortly after the onset of infection, they spun the cultured infected cells in a blender, shaking loose any parts of the phage that remained outside the bacteria.