What Is the Function of RNA?

The primary function of ribonucleic acid (RNA) is protein formation and synthesis. RNA also plays an essential role in gene expression and chemical catalysis of both peptide bond formation and other RNA molecules. In most cases, the main function of RNA is to carry a copy of an organism’s basic deoxyribonucleic acid (DNA) information into the proteins of newly-forming cells.

RNA is essential to any and all biological processes, as it is intricately involved in cell growth. Every living organism has a unique genetic coding that is stored in its DNA. DNA contains the basic “road map” for how an organism will grow and develop. A primary function of RNA is to translate the DNA into the protein structure of every new cell.

Enzymes known as RNA polymerase transcribe DNA into RNA. DNA and RNA are both macromolecules and are similar in many respects, but RNA is smaller, has but a single strand, and has a very different function. If the DNA is the instruction manual, the RNA is the worker: the function of RNA is to take the code and translate it into actual growth.

The RNA accomplishes this growth by engaging in new protein synthesis. A type of RNA known as messenger RNA, or mRNA, is what actually copies the DNA. MRNA binds to the DNA strand and forms a exact replica of the DNA bases. It journeys then to the ribosomes of new cells. The ribosomes are the sites of amino acid and protein formation.

In a ribosome, two different RNAs meet the mRNA. A transfer RNA, or tRNA, binds the mRNA to the amino acid, and facilitates the data transfer using the mRNA as a template. There is a different tRNA for each amino acid.

A ribosomal RNA, also known as an rRNA, binds each of these amino acids together, forming a peptide chain. If more than one amino acid is present in the chain, it is known as a polypeptide chain. Polypeptide chains with at least 50 total amino acids form proteins, which are essential for organic growth.

Sometimes things go wrong in the course of protein synthesis and genetic translation. When this happens, a tmRNA — a transfer-messenger RNA — will step in and get things going again. A ribosome may stall if there has been a translation error, either in the original RNA creation or in the translation. The tmRNA will clean and recycle the stalled ribosome, then destroy the errant mRNA. Organisms without properly functioning tmRNA molecules are generally more susceptible to stunted growth and other developmental problems.

The overall function of RNA is to create cells with genetic coding that exactly matches the host. Most of the time, this process happens in the course of normal, healthy growth. RNA also has a role in more destructive growth, including the growth of viruses. Many viruses replicate using RNA intermediates because of how efficiently the RNA copies and replicates genetic code.