Zoology - Molecular Basis of Inheritance Question with Solution | TestHub

Structure of polynucleotide chain

DNA = Polynucleotide.

Nucleotide = Nitrogenous base + Pentose sugar + Phosphate group.

As nitrogenous base and pentose sugar when linked, are also termed as nucleoside, so we can also say that : Nucleotide = Nucleoside + Phosphate group.

Linkages in a nucleotide molecule:

Nitrogenous base --(N-glycosidic linkage)-- Pentose sugar --(Phosphodiester linkage)-Phosphate group. Phosphate group is linked to$5\mathrm{’}\mathrm{ }–\mathrm{ }\mathrm{O}\mathrm{H}$of a nucleoside through the phosphoester linkage.