Watson and Crick

WATSON & CRICK

The article, "Structure for Deoxyribose Nucleic Acid", written by Watson and Crick, was a stepping stone on the path of discovery for the building blocks of life. In this article, Watson and Crick briefly state previous theories on the structure of DNA were incorrect in certain aspects but correct in others. Watson and Crick later went on to describe their version of a double helical structured DNA. They indirectly state the importance of their discovery which later them to winning the noble prize.

Previous to this publication, there were at least two other theories on the structure of deoxyribose nucleic acid. The first theory was that the structure "consisted of three intertwined chains, with the phosphates near the fiber axis, and the bases on the outside." (Watson and Crick, 4/2/53) This theory had been proposed by Pauling and Corey. Later a second theory was mentioned, but not very dwelled upon, in Watson and Crick's paper. Fraser had also suggested a triple wined chain. However, Fraser also suggested that "the phosphates are on the outside and the bases on the inside, linked together by hydrogen bonds." (Watson and Crick, 4/2/53)

Watson and Crick developed a double chained helix with the bases inside and the phosphates outside. By studying the Pauling and Corey theory, they discovered that where they had the phosphates and the bases were incorrectly placed because they would repel each other, therefore discovered the correct diagram. They also were able to correctly determine the correct base pairs which were adenine with thymine and guanine with cytosine. In their structure they show the double stranded helix twisted around the axis in which the base pairs are perpendicular to the axis. This determination of the base pairs and observation of the sequence is very important to the structure of DNA because in those specific pairings, it is suggested as a possible copying mechanism for the genetic material.

This last statement is where Watson and Crick state that they have now discovered the key to the understanding of life, "It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material." (Watson an Crick, 4/2/53) This copying mechanism for the genetic material would be the building