RNA

Abbreviation for ribonucleic acid; an essential substance for translating genetic information.

Like DNA, RNA consists of a sugar-phosphate backbone and a sequence of bases. Unlike DNA, the sugar in RNA is ribose and one of the four bases, T (thymine) is replaced by U (uracil).

The most important difference between DNA and RNA, however, is that RNA exists in the form of a single strand, rather than a double helix. The function of RNA is to transport and translate the information stored in the DNA. It also influences gene activity.

There are different forms of RNA. e.g.:

• Messenger RNA (mRNA) delivers the genetic information from the cell nucleus to the ribosomes, which are the sites of protein synthesis in the cell
• Ribosomal RNA (rRNA) is involved in the structural formation of ribosomes.
• Transfer RNA (tRNA) facilitates the linking of individual amino acids in the growing protein chain in the ribosomes.
• Small interfering RNA (siRNA) and micro RNA (miRNA) fulfil key functions in the regulation of cellular processes.