How Did Frederick Griffith's Experiments Contributed To The Discovery Of DNA?

From 1928 to 1952, experiments done by Frederick Griffith, Oswald Avery, Alfred Hershey, and Martha Chase all did experiments that contributed to the discovery of the DNA. Frederick Griffith experiment was done in 1928, Oswald Avery’ was done during the early 1940’s, and Alfred Hershey’s with help from Martha Chase was done in 1952. All of these experiments contributed to the idea known as translation, the process of cell ribosomes converting proteins to messenger RNA, or mRNA. Because of how they helped with discovering translation, these three experiments help lead to the discovery of DNA. Before Frederick Griffith’s experiment, no one knew anything about DNA or what it was. Frederick Griffith studied two types of Pneumococcus bacteria,
type III-S, and type II-R. Firstly, he injected both strains of the bacteria separately into two mouses and saw that the type-III-S, the one with smooth bacteria, killed the mice, while the type II-R with the rough bacteria kept the mouse alive. Next, he injected both strains of the Pneumococcus bacteria into the mouse and found that the type II-R was changed into type III-R and still killed the mouse. Griffith that only some molecules or a group of molecules changed rough bacteria into smooth bacteria with the process of transformation. Next, Avery in 1944 wanted to prove more on Griffith’s experiment by doing the same as he did, but changing it to prove his point. After injecting the rats with both types of the bacteria, he tried to reverse the effect of the heat-killed smooth bacteria by adding an enzyme to get rid of the proteins, lipids, carbohydrates, and RNA in the smooth bacteria. After he finished these experiments he found that only these nutrients once removed did not stop the process of transformation and where not in the process. However once the DNA was removed, it blocked the transformation and kept the rat alive. He then concluded that all genes were made of DNA. Lastly, the experiment of Hershey and Chase was on proving is Avery’s conclusion on his experiment was either true or false. Their experiment was they put radioactive isotopes on protein and DNA molecules to see which one was in the Bacteriophage. They found that the DNA molecule was in the Bacteriophage and conclude like Avery that genetic material is DNA, and not protein. All three of these experiments have shown the process of transformation in bacteria happens because of the newly found molecule called DNA.