DNA History

DNA was first purified in 1868 by Swiss scientist Friedrich Miescher in Tubingen,Germany, who named it Nuclein based on its location within the cell nucleus. However, research on the role of DNA in the new cells began in the early 20th century, along with the discovery of Mendelian genetics postulates. DNA and protein molecules that are considered the two most likely as a carrier of a genetic trait based on the theory. 

In 1953, James Watson and Francis Crick defines DNA as a polymer composed of fourbases of nucleic acids, two of the groups Purina : Adenine and Guanine, and two others from Pirimidina : Cytosine and Thymine

The four nucleobases are connected by phosphate glucose. Maurice Wilkins and Rosalind Franklin discovered that DNA is helical molecule that rotates every 3.4 nm, while the distance between molecules is 0.34 nm nucleobases, to be determined that there were 10 molecules in each round of DNA nucleobases. 

Having in mind that the diameter of the DNA helix around 2 nm, it was discovered that DNA is composed not of a chain, but the two helical chains. Final confirmation is done via the mechanism of DNA replication Meselson-Stahl experiment conducted in 1958.

DNA consists of two strands are twisted to form a double helix structure. In the double helix structure, the orientation of the chain of nucleotides on one strand opposite the orientation of the other strand of nucleotides. This is referred to as anti parallel. Each strand consists of a main frame, as the main structure, and nitrogen bases, which interact with DNA strands only in the helix. Both strands of the DNA double helix held together by hydrogen bonds between bases located on the second strand. 

Source from: Wikipedia

0 komentar:

Post a Comment


Copyright © 2011 About Mutation | Themes by Muta-Tion.