Ribonucleic Acid is a polymeric molecule implicated in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the three major macromolecules essential for all known forms of life. In eukaryotic cells, the two nucleic acids, ribonucleic acid (RNA) and deoxyribonucleic acid (DNA ), work together to direct protein synthesis.
Although it is DNA that contains the instructions for directing the synthesis of specific structural and enzymatic proteins, several types of RNA actually carry out the processes required to produce these proteins.
These include messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). Further processing of the various RNA’s is carried out by another type of RNA called small nuclear RNA (snRNA).
The structure of RNA is very similar to that of DNA, however, instead of the base thymine, RNA contains the base uracil.
In humans, the DNA molecule is made of phosphate-base-sugar nucleotide chains, and its three-dimensional shape affects its genetic function. In humans and other higher organisms, DNA is shaped in a two-stranded spiral helix organized into structures called chromosomes. In contrast, most RNA molecules are single-stranded and take various shapes.