Nucleic acid with postulate of Watson and Crick DNA

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Nucleic acid :
      Nucleic acid molecules are long chain polymers of nucleotides.The nucleic acid are considerable important biological system .Each of nucleic acid consists 3 component .ie Pentose sugar,Nitrogen base,Phosphate.
Similarly nucleic acid are of two type.ie Ribose nucleic acid(RNA) and Deoxyribose nucleic acid(DNA).
Deoxyribose nucleic acid(DNA):
       DNA is a nucleic acid containing the genetic instruction used in the development and functioning of all known living organism .Along with RNA and protein DNA is one of the 3 major macromolecules that are essential for all known forms of life.
Ribose nucleic acid(RNA):
    RNA is function in converting genetic information from genes into a amino acid sequence of protein .There are 3 universal type of RNA ie transfer (tRNA),messenger(mRNA), ribosomal(rRNA)
Artificial nucleic acid are analogous has been designed and synthesis by chemist and include peptied nucleic acid,morpholino and locked nucleic acid ,glycol nucleic acid and threose nucleic acid.
Pentose sugar :
        A pentose sugar is a monosaccharide with 5 carbon compound .This is ribose in case of RNA and Deoxyribose of DNA.
Nitrogen base:
       There are two types of nitrogen base ie purines and pyrimidines.Purines are double ring compound ie Adenine and Guanine.Pyrimidines are single ring compound ie Thyamine , Citosine and Uracil.
In DNA Thyamine is replaced by Uracil.
Phosphate bond:
In a nucleic acid phosphate bond is alternate with pentose sugar .This phosphate is responsible for the strong negative charge nucleotides and nucleic acid.
Postulate of Watson and Creic model of DNA

1.Each DNA molecules is composed of two long polynucleotides chains that run in opposite directions ,forming a double helix around the central axis.
2.There are about 10^10monomers of nucleotides in every DNA molecules.
3.The strands of DNA are complementry to each other.
4.The two strands of DNA are anti parallel to each others ie is the direction of phosphodiester bond in one strands to 5 to 3 whereas in othet 3 to 5 direction.
5. The two DNA strandsare head for each other by weak hydrogen bond.
6.The central portions of DNA molecules is occupied by nitrogen base in center and surrounded by phosphate bond and pentose sugar.
7.The pairing  of nitrogen base is very much specific ie T pair with A and C pair with G.
8.The distance between two nitrogen base pair sequence is 3.4A° There are 10 nitrogen base pair sequence in a one complete turn of 34A°.
9.The two DNA strands are separate with distance of 20A°.
10.On changing the PH or increasing the temperature two strands of DNA get separated by the break down of hydrogen bond between them.This is called denaturation of DNA.On bringing under normal condition denatured DNA will be form which is called renaturation.

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