Genetic information: nucleic acids
All living things, except viruses, have two types of nucleic acids: DNA and RNA. DNA is responsible for carrying genetic information, but for that information to be expressed it is necessary that various types of RNA intervene.
Nucleic acids are large polymers formed by the union of monomers called nucleotides linked by a phosphodiester bond, between the phosphate of one nucleotide and the pentose of the next nucleotide.
A nucleotide is made up of three components:
- A pentose. A five-carbon monosaccharide: ribose in RNA and deoxyribose in DNA.
- A phosphoric acid.
- To nitrogenous base:
- In DNA: adenine (A), guanine (G), cytosine (C) and thymine (T).
- In RNA: adenine (A), guanine (G), cytosine (C) and uracil (U).
- In DNA: adenine (A), guanine (G), cytosine (C) and thymine (T).
RNA is made up of a singlechain of nucleotides. Depending on their role, several types of RNA are distinguished: ribosomal RNA, messenger RNA, or transfer RNA.
By Calibuon at English Wikibooks [Public domain], via Wikimedia Commons
By Alejandro Porto [CC BY-SA 3.0], via Wikimdia Commons