DNA helix
Deoxyribonucleic acid (DNA) helix consists of two anti-parallel long poly nucleotide chains. These chains, or strands, are composed of four types of nucleotides and held together by hydrogen bonds between the nitrogen bases of nucleotides. The nucleotides are divided into two groups; purines of Adenine (A) and Guanine (G), and pyrimidines of Cytosine (C), Thymine (T). According to the Watson-Crick model of DNA, guanine (G) and Cytosine (C) bind together with three hydrogen bonds, whereas adenine (A) and thymine (T) bind with two hydrogen bonds. The DNA is formed into a double helix structure[1].
References
- ↑ Alberts B., Bray D., Hopkin K., Johnson A., Lewis J., Raff M., Roberts K., Walter P. (2010) Essential Cell Biology, Fourth Edition, New York: Garland Science. See pages 171-180.