Discuss the B-DNA helical structure
Watson & Crick suggested the double-helical structure of DNA in 1953. The backbone of the DNA molecule is made up of deoxyribonucleotide units joined by a phosphodiester bond. The DNA molecule consists of two chains wrapped around each other. The two helical strands are bound to each other by Hydrogen Bonds. Purines bind with pyrimidines A = T, C = G The pairing is specific and the two chains are complementary. One strand has the orientation 5’ → 3’ and other has 3’ → 5’. Both polynucleotides strands remain separated with a 20A° distance. The coiling is right-handed.
