Rna

Part of speech: noun

Definitions

1. A molecule essential for coding, decoding, regulation, and expression of genes
2. A nucleic acid that plays a crucial role in protein synthesis and gene expression processes
3. A biological polymer that serves as a template for the synthesis of proteins and as a key component in various cellular functions

Etymology: RNA is an abbreviation, not an old word: it stands for "ribonucleic acid." The "ribo" part comes from "ribose," the sugar that forms the backbone of the molecule, a name built from "arabinose" with the letters rearranged, reflecting its origin in gum arabic. "Nucleic" refers to the nucleus, where chemists first isolated these acids from cell material in the 1860s and 1870s. "Acid" was added because the molecules behaved as acids in the laboratory. The name took its present form in the early twentieth century, when researchers needed to distinguish this molecule from DNA, which contains deoxyribose instead of ribose. The "deoxy" prefix marks the sugar as lacking one oxygen atom, so the two names describe a single chemical difference. Both molecules were named by chemists for their structure rather than their function, and the function of RNA was only worked out over the following decades.

Synonyms: ribonucleic acid