mononucleotide

A mononucleotide is a chemical compound that serves as the fundamental building block for nucleic acids like DNA and RNA. Each mononucleotide is composed of three parts: a nitrogen-containing aromatic base, a five-carbon sugar, and a phosphate group.12

There are five possible nitrogen-containing bases: adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U). Adenine and guanine are purines, while cytosine, thymine, and uracil are pyrimidines. DNA contains A, G, C, and T, while RNA contains A, G, C, and U. The sugar in DNA is deoxyribose, and in RNA, it is ribose. The phosphate group links successive sugar molecules, forming phosphodiester bonds that create the long chains of nucleic acids. Mononucleotides are also involved in energy exchange within cells.134