umls-semnetwork:T114 | skos:definition | A complex compound of high molecular weight occurring in living cells. These are basically of two types, ribonucleic (RNA) and deoxyribonucleic (DNA) acids. Nucleic acids are made of nucleotides (nitrogen-containing base, a 5-carbon sugar, and one or more phosphate group) linked together by a phosphodiester bond between the 5' and 3' carbon atoms. Nucleosides are compounds composed of a purine or pyrimidine base (usually adenine, cytosine, guanine, thymine, uracil) linked to either a ribose or a deoxyribose sugar. | lld:umls |