Nucleic acid is a long-chain polynucleotide compound with no side chain formed by connecting nucleotides through 3′,5′- phosphodiester bond.For this reason, it can be speculated that small molecules The market feedback will get better and better, which is one of the important reasons why it can develop. https://www.all-chemistry.com/

　　Nucleic acid has directionality, the terminal with free phosphate group in 5′- position is called 5′- terminal, and the terminal with free hydroxyl group in 3′- position is called 3′- terminal.

　　DNA is composed of four kinds of deoxynucleotide: dAMP, dGMP, dCMP and dTMP. Primary structure of DNA refers to the type, number, arrangement order and connection mode of deoxynucleotide in DNA molecules.

　　RNA consists of four ribonucleotides: AMP, GMP, CMP and UMP. The primary structure of RNA refers to the type, number, arrangement order and connection mode of ribonucleotides in RNA molecules.