Question

Nucleic acid exhibit secondary structure . describe through Watson crick model...??​

Answer 1

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Nucleic acids show awide range of secondary structures. A secondary structure is the set of interactionsbetween bases and sugar phosphate backbone and is responsible for the shape thatnucleic acid. James Watson and Francis Crick proposed a secondary structure of DNA moleculesbased on the crystallographic studies.♥️

Answer 2

Answer:

Explanation:

Nucleic acids exhibit a wide .variety of secondary structures. For example, one of the secondary structures exhibited by DNA is the famous Watson- Crick model.

This model says that DNA exists as a double helix. The two strands of polynucleotides are antiparallel, i.e. run in the opposite direction. The backbone is formed by the sugar—phosphate—sugar chain.

The nitrogen bases are projected more or less perpendicular to this backbone but face inside. A and G of one strand compulsorily base pairs with T and C, respectively, on the other strand. There are two hydrogen bonds between A   and T and three hydrogen bonds between G and C.

Each strand appears like a helical staircase. Each step of ascent is represented by a pair of bases. At each step of ascent, the strand turns 36°. One full turn of the helical strand would involve ten steps or ten base pairs.

Attempt drawing a line diagram. The pitch would be 34 A. The rise per base pair would be  3.4 A. This form of DNA with the above mentioned salient features is called B-DNA