called ester bonds, between the sugar base of one nucleotide and the phosphate group of the adjacent nucleotide. The sugar is the 3' end, and the phosphate is the 5' end of each nucleiotide.

Phosphorylation is the enzymatic process through which a phosphate group is added via an ester bond, generally by a kinase, to either a small molecule or a protein. Protein phosphorylation is ...