The Phosphodiester Bond

Nucleic acids (RNA and DNA):

formed by the condensation of nucleotides, catalyzed by polymerases.

The bond:  a phosphodiester bond.

The bond is shown in figure a display of a trinucleotide DNA fragment.



A couple of shorthand notations to designate nucleic acid polymers:
vertical lines represent the sugars
diagonal lines represent the phosphodiester bonds.



More commonly: only indicate the order of bases and the direction of the polymer chain. For instance:

5' - AGTCCGATGCAAGCTCG - 3'

The complementary sequence:

5'-AGTCCGATGCAAGCTCG-3'
3'-TCAGGCTACGTTCGAGC-5'


proposed by James Watson and Francis Crick.