noun, plural: ribonucleic acids
A nucleic acid refers to any of the group of complex compounds consisting of linear chains of monomeric nucleotides. Each nucleotide is composed of phosphoric acid, sugar and nitrogenous base. Nucleic acids may be in the form of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA).
Ribonucleic acid, or RNA, is a single-stranded nucleic acid as opposed to the deoxyribonucleic acid, which is double-stranded. However, some viral RNAs and siRNA are double-stranded.
Structure: Ribonucleic acid (RNA) is a molecule consisting of a long linear chain of nucleotides. Each nucleotide unit is comprised of a sugar, phosphate group and a nitrogenous base. It differs from a DNA molecule in a way that the sugar backbone is a ribose (deoxyribose in DNA) and the bases are adenine, guanine, cytosine and uracil (thymine in DNA).
- protein synthesis (e.g. mRNA, tRNA, rRNA, etc.)
- post-transcriptional modification or DNA replication (e.g. snRNA, snoRNA, etc.)
- gene regulation (e.g. miRNA, siRNA, tasiRNA, etc.)