-
Fredrich Miescher
Fredrich Miescher a swiss physician was one of the first people to contribute to what we know now as DNA. Fredrich Miescher studied leucocytes founf in puss. Miescher isolated the nuclei in the leucocytes and found a substance made of nitrogen and phosphorus. He called this substance nuclein, which later became deoxyribonucleic acid. -
Erwin Chargaff
Erwin Chargaff ran several experiments in through 1944 to 1950. In 1950 Chargaff published facts important for future DNA structures. Chargaff stated: 1,the number of adenine residues always equals the number of thymine residues; 2,the number of guanine residues always equals the number of cytosine residues;and 3,the number of purines always equals the number of pyrimidines. Chargaff also concluded that these rules are still in effect even though the ratio changes from one organism to another. -
Alfred Hershey and Martha Chase
Alfred Hershey and Martha Chase were out to prove in the 1950's that proteins carry genetic information. They ran an experiment that tracked the transfers of proteins and DNA between a virus and its host. However they found that protein did not move in these experiment but DNA did. This proved that protein did not contain genetic information but DNA did. -
Rosalind Franklin
Rosalind Franklin was a crucial part of the discovery of DNA. Like Watson and Crick, Franklin attended Cambridge. Franklin took X-rays of DNA fibers. She was able to get two sets of high-resolution crystallized DNA fibers. She discovered the basic structures of a DNA strand and found that phosphates are on the outside. These pictures helped Watson and Crick create their model of DNA. -
Watson and Crick
James Watson and Francis Crick were Cabridge students studying DNA. Their goal was to create a model of what DNA truly looks like. They had a failed attempt and did not correctly identify DNA until they observed the x-ray diffractions of Franklin. Watson and Crick observed that the DNA structure is in the shape of a double helix , with two chains of nucleotides on each helix. With Chargaff's base pairing the two found that the matching base pairs interlock in the middle of the helix. -
Mathew Meselson and Franklin Stahl
Mathew Meselson and Frank Stahl in 1958, were trying find out how DNA replicates. They created an experiment to see if the original DNA strand was found in the daughter cell . The scientist would extract DNA in different mediums. They found that DNA replicates semi-conservatively because The DNA density was not the same as the parent cell. This is because the parent cell does not pass down the same density of DNA to the daughter. This experiment helped scientist discover how DNA is passed down. -
Bibliography
"Erwin Chargaff." Biography - Famous Biologists. N.p., n.d. Web. 22 Jan. 2017.
"The Hershey-Chase Blender Experiments." PaulingBlog. N.p., 29 Oct. 2015. Web. 22 Jan. 2017.
"Concept 19 The DNA Molecule Is Shaped like a Twisted Ladder." Rosalind Franklin :: DNA from the Beginning. N.p., n.d. Web. 22 Jan. 2017.
Nature.com. Macmillan Publishers, n.d. Web. 22 Jan. 2017. -
Bibliography
"Meselson–Stahl Experiment." Wikipedia. Wikimedia Foundation, n.d. Web. 23 Jan. 2017.
Elsevier Inc. "Friedrich Miescher and the Discovery of DNA." Friedrich Miescher and the Discovery of DNA. Elsevier Inc., 2004. Web. 22 Jan. 2017.
