Q.Write Salient feature of DNA double Helix
Or
Describe Watson-crick model of DNA
Ans:- (i) DNA is made up of two polynucleotide chain.
(Sugar phosphate Backbone) (Nitrogenous Base project Inside)
(ii) one Chain --> 5'-3' direction & Another 3'-5 direction
(Antiparallel polarity)
(iii) Purine Base Pair with pyrimidine.
A=T (Two H-bond)
G≡ C (Three H-bond)
(IV) DNA Right handed coil, Each turn pith→ 3.4nm
1 turn = 10 Base pair
So, Distance Between two Base Pair = 0.34 nm
(v) Base pair stacked over Each other
