The role of RNA, ribonucleic acid, is an important yet varied one in the human body. Among these crucial roles are catalyzation and initiation of biological reactions, control of gene expression, cellular communication, and ultimately, the synthesis of different types of proteins. The role of RNA is so important that, along with DNA and proteins, this molecule is considered one of the three macromolecules necessary to sustain life. It is possible that forms of life may exist that do not depend on these three macromolecules, but to date none have been discovered.
Very similar in composition and function to its counterpart, DNA, RNA differs in three unique ways. The first is that it is single stranded, whereas DNA is a double helix. Secondly, RNA contains ribose rather than deoxyribose, and thirdly, adenine's complimentary base in RNA is uracil rather than thymine, which is the case with DNA. Functionally, the role of RNA differs in that it is more involved in transcription and translation, while DNA may be thought of as more of a template containing genetic information.
RNA is synthesized using DNA as a model molecule. This process, termed transcription, is initiated by a catalyst molecule named RNA polymerase. Then, RNA serves as a more functional version of DNA, allowing genetic material to dictate particular protein synthesis within the body. The specific proteins synthesized dictate various bodily characteristics that shape the biological individuality of a particular person.
The genetic information that is contained within these molecules is of course different for everyone. Although relatively similar, simple differences in RNA makeup may change the role of RNA in the body by causing different reactions. RNA is comprised of nucleotides, the four most common being adenine, guanine, uracil, and cytosine. The unique order of these nucleotides within the molecule is the force behind genetic variation. As was previously eluded to, DNA also has these nucleotides but contains thymine in the place of uracil.
There are different forms of RNA that exist within the body too. The most common alternative forms of this molecule are messenger RNA (mRNA) and transport RNA (tRNA). The role of RNA in these forms, as the names may suggest, are to carry copies of protein synthesis instructions from the DNA elsewhere and to transport amino acids into their proper places during molecule manufacturing. Although it is impossible to summarize the vast roles covered by this molecule in a brief manner, this article outlines the basic roles that RNA carries in the living world.