DNA and RNA biosynthesis
Deoxyribonucleic acid (DNA), which associated with basic proteins called histones constitutes the chromosomes, is the holder of biological information. Its replication allows the reproduction of species, its transcription the cellular function via the protein synthesis, enzymes, carriers, receptors etc
The enzymes necessary for the synthesis of DNA from the molecules provided by the external medium are themselves synthesized under the control of DNA, relayed by the ribonucleic acid, RNA.
Bacteria have two nucleic acids DNA and RNA, whereas viruses have only one of them, either DNA or RNA.
The components of ribonucleic and deoxyribonucleic acids are a purine base (adenine, guanine) or a pyrimidine base (cytosine, thymine, uracil), a sugar (either D-ribose or D-deoxyribose) and one, two or three molecules of phosphoric acid. The structures base + sugar are called nucleosides and ribonucleosides (adenosine, guanosine, cytidine and uridine) and deoxyribonucleosides (deoxyadenosine, deoxyguanosine, deooxycytidine and deoxythymidine). When phosphorylated, the nucleosides are called nucleotides, ribonucleotides and deoxyribonucleotides. The biosynthesis of DNA and RNA is a complex phenomenon involving a great number of steps.
On the pharmacologic level, the alteration of DNA and RNA synthesis can inhibit the development of microorganisms (bacteria, viruses, parasites) and tumors. This inhibition can be obtained at two levels