The structure of nucleic acids. Type of connection between mononucleotides??

Two types of bonds hold nucleotides together: the phospho-ester bond, which connects the phosphate group to the 5 hydroxy group on the ribose sugar, and the glycosidic bond, which forms the monomers of nucleotides, connects the anomeric carbon on the ribose sugar to the N atom on the base (GTACU). This type of glycosidic bond is also referred to as an N-linked glycosidic bond.

The two critical reactive ends of all nucleotide monomers are the 3 hydroxyl group on the ribose sugar and the 5 phosphate group.

The phosphate group that links two monomers for a dimer (dinucleotide) contains two ester bonds, one to each monomer. The 5 phosphate of one monomer forms a phosphoester bond with the 3 hydroxyl group of the other monomer.

A phospho-diester bond is the connection between the monomers in a dinucleotide. Since the dinucleotide still has a free 3 hydroxyl group, the following monomer can attach itself to this site to create a trimer, and so on, to an oligonucleotide, polynucleotide, etc.

Phosphodiester bonds bind mononucleotides together to form nucleic acids.