and a nitrogenous base. Adjacent ribose nucleotide bases are chemically attached to one another in a chain via chemical bonds called phosphodiester bonds. Unlike DNA, RNA is usually single-stranded.

Kossel isolated cytosine from calf thymus tissues and found that it was a component of nucleic acids. This discovery, along with the identification of other nitrogenous bases, laid the foundation for ...

and several nitrogen-containing bases. Later it was found that the sugar in nucleic acid can be ribose or deoxyribose, giving two forms: RNA and DNA. In 1943, American Oswald Avery proved that DNA ...

highlighting the numbering of the carbon and nitrogen atoms. The purine structure consists of a pyrimidine ring (positions 1 to 6) fused to an imidazole ring (positions 7 to 9). Adenine and guanine, ...

RNA is formed by linking molecules of ribose (a monosaccharide) with phosphate groups that bind to four types of nitrogenous bases: adenine (A), guanine (G), cytosine (C) and uracil (U). Both the ...