What is a nucleotide?

A nucleotide is a fundamental building block, or monomer, that forms nucleic acids such as DNA and RNA. Each nucleotide consists of three components: a phosphate group, a sugar molecule (deoxyribose in DNA and ribose in RNA), and a nitrogenous base (adenine, thymine, cytosine, guanine for DNA; adenine, uracil, cytosine, guanine for RNA). These components together allow nucleotides to link through phosphodiester bonds, creating long chains of nucleic acids that store and transmit genetic information.

Understanding that nucleotides are specifically related to nucleic acids distinguishes them from other biological molecules such as proteins, lipids, and other structures that fulfill different roles within a cell. The role of nucleotides as essential units of nucleic acids is crucial for processes such as replication, transcription, and gene expression.