What is the phosphodiester bond and how is it drawn?
Nucleotide Monophosphates, NMPs, are nucleosides that have 1 phosphate group. Here is GMP.
All simple nucleotides have this phosphoester bond.
When one nucleotide makes a linkage with another nucleotide, the phosphate group (which already has 1 ester bond) makes a 2nd ester bond. This becomes a phosphodiester bond.
In the picture below, the phosphate group has one ester bond to the nucleotide below, and one ester bond to the nucleotide above. This is the phosphodiester bond.