Guanine

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Guanine is one of the five main nucleobases found in nucleic acids (e.g., DNA and RNA). Guanine is a purine derivative, and in Watson-Crick base pairing forms three hydrogen bonds with cytosine. Guanine "stacks" vertically with the other nucleobases via aromatic interactions. Guanine is a tautomer (see keto-enol tautomerism). The guanine nucleoside is called guanosine.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Guanine is also the name of a white amorphous substance found in the scales of certain fishes, the guano of sea-birds, and the liver and pancreas of mammals. In fact, the name of the nucleobase is derived from the term 'guano', because it was first isolated from bird manure.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Nucleic acid: A nucleic acid is a complex, high-molecular-weight biochemical macromolecule composed of nucleotide chains that convey genetic information. The most common nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic acids are found in all living cells and viruses....

DNA: :For other uses, see DNA (disambiguation)....

RNA: Ribonucleic acid (RNA) is a nucleic acid consisting of a string of covalently-bound nucleotides. It is biochemically distinguished from DNA by the presence of an additional hydroxyl group, attached to each pentose ring. While RNA usually contains uracil instead of thymine, this is not always true, f...