Describe the structure of DNA as proposed by Watson and Crick.

Explanation

(1) Watson and Crick shared the Nobel Prize in 1962 for their discovery, along with Maurice Wilkins, who had produced the crystallographic data supporting the model. Rosana Franklin (1920-1958) had earlier produced the first clear crystallographic evidence helical structure. James Watson and Francis Crick of Cavendish laboratory in CambrisBiomolecules B-117 built a scale model of double helical structure of DNA which is the most prevalent form ofDNA, the B-DNA. This is the secondary structure of DNA.
(ii) As proposed by James Watson and Francis Crick, DNA consists of right handed double henx with 2 helical polynucleotide chains that are coiled around a common axis to form anded B form of DNA. The coils are held together by hydrogen bonds which occur between complementary pairs of nitrogenous bases. The sugar is called 2.-deoxyribose re is no hydroxyl at position 2.. Adenine and thiamine base pairs has two u bonds while guanine and cytosine base pairs have three hydrogen bonds. Chargaff.s Rule: •A-T, G=C
• A+G=T+C
•A:T=G:C=1
(iii)As published by Erwin Chargaff in 1949, a purine pairs with pyrimidine and vice versa. Adenine (A) always pairs with Thymine (T) by double bond and Guanine (G) always pairs with Cytosine (C) by triple bond.