RNA Structure

Each nucleotide in RNA contains a ribose sugar, with carbons numbered 1 'to 5'. A base is fixed in position 1, usually adenine (A), cytosine (C), guanine (G) or uracil (U). The purines are adenine and guanine, cytosine and uracil are pyrimidines. A phosphate group binds to the 3 'position of ribose and the 5' position of the other. The phosphate groups are negatively charged, each at physiological pH, making RNA a charged molecule (polyanion). The bases can form hydrogen bonds between cytosine and guanine, adenine and uracil and between guanine and uracil medium. [4] However other interactions are possible, as a group of adenine bases binding to each other in a flash, [5] and has a GNRA tétraboucle [base pairs guanine-adenine 4].