singlenucleotide

A single nucleotide is the basic building block of nucleic acids, consisting of a sugar molecule (deoxyribose in DNA or ribose in RNA), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine in DNA; adenine, uracil, cytosine, or guanine in RNA). The sugar and phosphate form the backbone of DNA and RNA, while the base carries the informational content through base pairing and sequence.

In DNA, nucleotides pair through hydrogen bonds: adenine with thymine and cytosine with guanine, enabling the double helix structure. In RNA, the bases pair differently in structural contexts, with adenine pairing with uracil and cytosine with guanine in folded molecules. Beyond information storage, nucleotides function as monomers for the polymers that encode, transmit, and regulate genetic information, and as energy carriers such as ATP, GTP, and their derivatives.

Single nucleotide polymorphisms (SNPs) are variations at a single nucleotide position among individuals. SNPs can occur in coding regions, potentially changing amino acids or protein function; in regulatory regions, they can influence gene expression; or in noncoding regions with other effects. Most SNPs have no overt effect, but some are associated with traits or diseases and are widely used in genetic mapping and association studies.

In research and biotechnology, single nucleotides are synthesized with precision, read by sequencing technologies, and manipulated by genome-editing methods. Understanding nucleotide identity and variation is fundamental to genetics, molecular biology, and modern genomics.