Glossary of termsAdenine Adenine is a purine derivative, one of the two purine bases involved in the formation of nucleotides, the structural units of DNA and RNA. In DNA, adenine binds (complementary) to thymine through two hydrogen bonds, which helps to stabilize the structure of the nucleic acid. In RNA, adenine binds to uracil (remember that in eukaryotes, RNA is a single-stranded structure). Adenine forms:
- several tautomers (substances that can be rapidly converted into each other and are often considered equivalent);
- adenosine, a nucleoside, when it binds to ribose and deoxyadenosine when it binds to deoxyribose
- adenosine triphosphate (ATP), a nucleotide that has three phosphate groups attached to adenosine. ATP is used in cellular metabolism as one of the main methods of transferring chemical energy between chemical reactions.
In addition, adenine is a component of AMP (which acts as a secondary messenger in the body), NAD, NADP and FAD - coenzymes that are actively involved in redox processes.
In the old literature, adenine is sometimes referred to as vitamin B4. However, today it is no longer considered a B vitamin. It is believed that, at the origin of life on Earth, the first adenine was formed by the polymerization of five molecules of hydrogen cyanide (HCN).
Physical properties:
Adenine is a colorless crystal that melts at 360-365 °C. The molecular expansion coefficient is 13500.
Chemical properties:
Chemical formula C5H5N5, molecular weight 135.14 g/mol. Adenine exhibits basic properties (pKa1=4.15; pKa2=9.8). When reacting with nitric acid, adenine loses its amino group and is converted to hypoxanthine (6-oxypurine). In aqueous solution, it crystallizes into a crystallohydrate with three water molecules. <<< |
