Definition: Adenine, a nucleotide in DNA, is a sugar-phosphate linkage molecule that links two carbon-carbon bonds between adenine (A) nucleotides. The structure of adenine is a tetrahedral shape, with the nitrogen atom on one end and the three phosphodiester linkers on the other two ends. The ring around the nitrogen atom contains six double-bonded pairs of nitrogen atoms, which are linked to each other by hydrogen bonds. Adenin is a very reactive nucleotide because it is easily oxidized to adenine and acetyladenine (also called pyrimidine diphosphate) or to thymine. In DNA, adenine is converted into purine in the presence of uracil, while thymine becomes adenine in the absence of uracil. Adenin binds to DNA by hydrogen bonds, which are strong but reversible. The two nitrogen atoms in a double bond can be bonded together or separated by a phosphodiester link, resulting in either an adenine-adenine or purine-thymine pairing. This binding allows adenine to interact with DNA to form the major structural component of DNA. Adenin is the only nucleotide that is completely unpaired; it is not paired with any other nucleotide except for uracil and pyrimidine diphosphate (7-aminotrimethylsulfonylphosphonic acid) (ATP). Adenin can be produced synthetically through an enzyme called adenine dehydrogenase, which catalyzes the addition of a hydroxyl group to adenine. This process is used in many biochemical applications, including genetic modification and DNA repair mechanisms. Overall, adenine plays a crucial role in DNA structure, function, and regulation, contributing to the integrity and stability of cellular life.

adenin

Definition: The word "adenine" is a nucleotide, which is a single 3-carbon sugar molecule that carries one deoxyribonucleic acid (DNA) adenine (A), two cytidine (T), four uracil (U) and eight thymine (T). It is found in all living cells of the body. The adenine nucleotide is also known as the "d" or "D" form, and it forms the backbone of DNA strands and RNA molecules. Adenine has a specific biological function. The base plays a crucial role in the structure and function of proteins and enzymes. It serves as an essential component for the synthesis of DNA, which is the genetic material that carries instructions for the production of cells. In addition to its role in gene expression, adenosine also functions as a building block for DNA replication. Adenine can be found in several nucleic acid molecules, including DNA and RNA. It is primarily found in organisms where DNA synthesis occurs, such as bacteria, viruses, and certain types of fungi. Adenine is also present in nature, but its distribution and function are not well understood. It is important to note that the definition of a specific term can vary between different sources and disciplines. This could be due to differences in terminology or cultural usage within different communities or fields.

adenine

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