Nucleic acids exhibits secondary structure. Justify with example

Explanation

. Nucleic acids exhibit a wide variety of seconary structure. For example, one of the secondary structures exhibited by DNA is Watson - Crick modei. According to this, DNA oxists as a double helix. The two stands of polynucleotides are antiparallel i.e., run in the opposite direction. The back bone is formed by the sugar-phosphate, sugar chain. The nitrogen bases are projected more or less perpendiular to this backbone but face inside. A combines with T by two hydrogen bonds where G combines with C by three hydrogen bonds. One full turn of the helical strand would involve ten base pairs. The length of one coil is 34 A and the distance between base pair is 3.4 A. This type of DNA is called B-DNA.