Editing Nucleotide base (section)

==Structure==
[[File:DNA chemical structure.svg|thumb|350px|Chemical structure of DNA, showing four nucleobase pairs produced by eight nucleotides: adenine (A) is joined to thymine (T), and guanine (G) is joined to cytosine (C). +&nbsp;This structure also shows the [[directionality (molecular biology)|directionality]] of each of the two phosphate-deoxyribose backbones, or strands. The 5' to 3' (''read'' "5 prime to 3 prime") directions are: ''down'' the strand on the left, and ''up'' the strand on the right. The strands twist around each other to form a double helix structure.]]

At the sides of nucleic acid structure, phosphate molecules successively connect the two sugar-rings of two adjacent nucleotide monomers, thereby creating a long chain [[biomolecule]]. These chain-joins of phosphates with sugars ([[ribose]] or [[deoxyribose]]) create the "backbone" strands for a single- or double helix biomolecule. In the double helix of DNA, the two strands are oriented chemically in opposite directions, which permits base pairing by providing [[complementarity (molecular biology)|complementarity]] between the two bases, and which is essential for [[DNA replication|replication]] of or [[transcription (genetics)|transcription]] of the encoded information found in DNA.{{cn|date=May 2024}}