Introduction
In 1953 three biochemists Francis Crick, James Watson and Rosalind
Franklin solved the mystery of life by working out the structure of
DNA. Deoxyribonucleic acid (DNA) is a Double stranded helical
molecule. It consists of two sugar- phosphate backbone on the
outside, held together by hydrogen bonds between pairs of
nitrogenous bases. The bases are of four types they are A, C, G and T
pairing always occurring between (A & T) and (C & G). DNA Molecules
stores genetic information about family, growth, development. In the
1950s biochemists realized that DNA, short for deoxyribonucleic acid,
delivered the instructions for copying a new organism. A yard of DNA
folded and packed into the nucleus of every cell in pairs called ‘’
chromosomes’’, with one exception in the reproductive cells, where
the pieces of DNA are not paired.
James Watson, Francis Crick and Rosalind Franklin
In 1952 the first x-ray picture of DNA was taken, which led to
Discovery of molecular structure by James Watson and Francis Crick.
They used X – ray crystallography to identify that the DNA is made up
of two wrapped strands around each other to produce double helical
structure. James Watson and Francis crick created a milestone by
determining the structure of DNA. They even used Chargaff principle.
They determined that DNA can pass through successive generations.
Watson, Crick and Franklin thought that understanding DNA structure
would help them to know how the molecules are coded the
instructions for coping the another organism. They started to take the
images of crystals of DNA. The pattern of x-ray bouncing off atoms
gave information about their location in the molecule. Watson know
that Franklin’s photograph that DNA had to be helix with certain
dimensions. He draw up models that machine shop would construct
out metal and wire. Franklin believed answers would come more with
X-ray images. Firstly, they tried using two strands, putting them in the
center of the model with bases on the outside, but this didn’t produce
any chemically acceptable structure. Now, they played around with
the shapes of the four bases, using paper models and combining them
in different ways. Finally, they visualized a structure that solved the
puzzle. If two of the bases were bonded in pairs (G with C), they took
up the same space as the other pair (A with T). Hence, they could be
arranged like steps on a spiral staircase inside of two strand of sugarphosphates running in opposite directions.
Conclusion
In April 25, 1953 the issue of nature published Francis Crick and James
Watson’s article, “A structure for Deoxyribose nucleic acid. In 1962
James Watson and Francis Crick received the noble prize in
Medicine/physiology for their work. Franklin could not receive the
prize because she passes away. She had died due to ovarian cancer
Abstract
James Watson, Francis Crick and Rosalind Franklin work out the
structure of DNA. Research has shown that how Crick and Watson
discover the structure of DNA, and the methods. This study aims to
determine that DNA has genetic information
Information in this guide was obtained from:
1. https://www.khanacademy.org/science/biology/dna-as-the-genetic-material/dna-discoveryand-structure/a/discovery-of-the-structure-ofdna#:~:text=In%20Watson%20and%20Crick's%20model%2C%20the%20two%20strands%20
of%20the,just%20any%20combination%20of%20bases
2. https://homework.study.com/explanation/what-methodology-did-watson-and-crick-use-todetermine-the-structure-ofdna.html#:~:text=Answer%20and%20Explanation%3A&text=Watson%20and%20Crick%20ar
e%20famous,produce%20a%20double%2Dhelical%20structure.
3. https://www.khanacademy.org/humanities/big-history-project/life/knowing-life/a/crickwatson-and-franklin2
4. https://homework.study.com/explanation/what-methodology-did-watson-and-crick-use-todetermine-the-structure-ofdna.html#:~:text=Answer%20and%20Explanation%3A&text=Watson%20and%20Crick%20ar
e%20famous,produce%20a%20double%2Dhelical%20structure.
5. https://www.khanacademy.org/humanities/big-history-project/life/knowing-life/a/crickwatson-and-franklin2