Definition: Adenine is a nucleotide (a chemical building block of DNA) found in all living things, including humans. It is composed of three nitrogen atoms bonded to a phosphate group at its central carbon position. Adenines are also known as uracil or U. The term 'adenine' was introduced into scientific literature in 1958 by the chemist J.J. Fadiman and has since become a standard term for nucleotides. The term is used primarily to distinguish between two different types of adenine: 1. Adenine (A) - The most abundant form of adenine, found in all living organisms. 2. Thymine (T) - A thymine atom bonded to a nitrogen atom at the 5' position of an adenine and surrounded by four phosphates. It is one of three bases that make up DNA, along with Adenine and Guanine. Adenine is one of eight bases commonly found in DNA molecules, accounting for about 70% of the nucleotide sequence of DNA. In a single DNA molecule, adenines are paired, forming two strands of the double helix structure known as the twin helix of DNA. Each strand consists of two copies of adenine and two copies of thymine. The exact sequence of adenine and thymine in each DNA strand is determined by specific genetic codes that determine which base is complementary to which base within the DNA molecule. This allows for precise control over the structure and function of DNA, as well as for the regulation of cellular processes such as transcription and translation.

adenines