Nucleotides are the monomers of nucleic acids, which include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Each nucleotide consists of three components: a phosphate group, a five-carbon sugar, and a nitrogenous base. The sequence of these nucleotides determines the genetic information carried by the nucleic acid, playing a crucial role in coding, decoding, regulation, and expression of genes.
In DNA, nucleotides pair up in specific ways (adenine with thymine, and cytosine with guanine) to form the double helix structure. In RNA, however, adenine pairs with uracil instead of thymine. This unique structure and pairing are fundamental to the processes of replication and transcription, allowing for the accurate transfer of genetic information.