Ribonucleic acid (RNA) occurs in all living things, including bacteria, plants, animals, and fungi. It is an important molecule that aids in gene expression and protein synthesis. Messenger RNA (mRNA) transfers genetic information from DNA to ribosomes, where proteins are made. Other forms of RNA, including ribosomal RNA (rRNA) and transfer RNA (tRNA), aid in the assembly of amino acids into proteins. Some viruses, such as RNA viruses, even employ RNA as their genetic material rather than DNA.
In addition to protein synthesis, RNA has important functions in gene regulation and cellular processes. Gene expression is controlled by small interfering RNA (siRNA) and microRNA (miRNA) by silencing or activating genes. Ribozymes, which are RNA molecules, have the ability to catalyze biochemical reactions. The discovery of the various functions of RNA underscores its importance in evolution and cellular complexity. Because RNA is crucial for basic biological processes, it is found in all living organisms, showing its universal function in life.