The structure of nucleic acids. Type of connection between mononucleotides??
Nucleotides have two kinds of connections that hold them together. The first is the glycosidic bond from the anomeric carbon on the Ribose sugar to the N atom on the base (GTACU). This is sometimes called an N-linked glycosidic bond.
The other connection is a phospho-ester bond from the 5` hydroxy group on the ribose sugar to a phosphate group. These connections make up the monomers of nucleotides.
All nucleotide monomers have 2 important reactive ends. The 5
Phosphate and the 3 Hydroxyl group on the ribose sugar.
When 2 monomers for a dimer (dinucleotide), the 5
Phosphate of one monomer forms a phosphoester bond with the 3 hydroxyl group of the other monomer. The phosphate group that is linking them contains 2 ester bonds - one to each monomer.
The linkage between the monomers in a dinucleotide is called a phospho-diester bond. Now your dinucleotide still has a free 3` hydroxyl group, so the next monomer can add onto this site and you'll get a trimer...and on and on...to an oligonucleotide...polynucleotide, etc.