Ribonucleic acid (RNA)
The ribonucleic acid or RNA comprises nucleotides of ribose, with the nitrogenous bases adenine, guanine, cytosine and uracil. So it does not have thymine like DNA, except for tRNA. Ribonucleotide binding is via 5'→3' phosphodiester bonds, as in DNA, but RNA is almost always single-stranded.
Although RNA presents a primary structure that is the sequence of ribonucleotides of the chain, it also has folded areas in which hydrogen bonds are established between the complementary bases, AU and GC, originating a certain double-stranded secondary structure of double helix, similar to that of DNA.
RNA is responsible for using the information contained in DNA to carry out protein synthesis.
RNA also has a biocatalytic function, so it is believed that, when life originated, they could be the first molecules capable of self-duplication, although later it would be DNA, with its much more stable chain, that would be in charge of storing the information genetics.
You can find RNA made up of one or two strands:
- Double-stranded RNA (in reoviruses).
- Single-stranded RNA, such as transfer RNA (RNAs or tRNA), messenger (mRNA), ribosomal (rRNA) and nucleolar (RNAn).