Dna Scientist

Front 1

Griffith

Back 1

-wanted to learn how certain types of bacteria produce pneumonia
-isolated 2 strains (types) of pneumonia bacteria from mice:: the disease-causing grew smooth colonies and the harmless produces rough edged colonies
-tested on mice:: 1. harmful-->died, 2.harmless-->lived, 3.heat-killed-->lived, 4.heat-killed + harmless-->died
-concluded that the disease-causing factor was transferred::transformation

Front 2

Avery, Macleod, McCarty

Back 2

-determines which molecule in the heat-killed bacteria is most important for transformation
-treated an extract from the H-K bacteria with enzymes that killed RNA-->transformation still occurred
-repeated with enzymes that break down DNA-->no transformation occurred
-concluded that DNA stores and transmits the genetic information from one generation of an organism to the next

Front 3

hershey and chase

Back 3

-studied viruses
-uses 32P and 35S as markers for DNA and proteins
-the bacteriophages injects genetic info. into a bacterium and results in raioactivity inside bacterium with 32P
-concluded that the genetic information of the bacteriophage was DNA, not protein

Front 4

chargaff

Back 4

-discovered that the percentage of guanineG and cytosineC bases are almost =, adenineA and thymineT are almost =
chargaff's rule: A = T; G = C

Front 5

franklin and wilkins

Back 5

Franklin used X-ray diffraction to get info. about DNA's structure
-X-shaped pattern shows the strands of DNA are in helix shape
-the angle of the X suggest that there's 2 strands
-nitrogenous bases are near the center of the molecule

Front 6

watson and crick

Back 6

tried to understand the DNA by building 3-D models
-shown Franklin's work and using the clues, built another model that explains how DNA carry information, and how it's copied
-hydrogen bonds form between A and T, G and C, with neough force to hold the 2 strands together, which explains Chargaff's rule