Definition of Ribonucleic acids (RNA)

1. Linear polymer molecules composed of a chain of ribose units linked between positions 3 and 5 by phosphodiester groups. The bases adenine or guanine (via atom N-9) or uracil or cytosine (via atom N-1), respectively, areattached to ribose at its atom C-1 by -N-glycosidic bonds (see nucleotides). The three most important types of RNAs in the cell are: messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rR