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:
proposed by James Watson and Francis Crick.