Nucleosides are substances present in organisms as intermediate products of metabolism. Some species of mold and fungi synthesize some of them with antibiotic activity. Nucleosides are obtained by elimination of phosphoric acid from a nucleotide, the structural unit of nucleic acids. A nucleoside is therefore a compound consisting of a nitrogenous base, purinic or pyrimidine, and a pentose sugar, bound by a β-glycosidic bond.
What are the structural differences between a nucleoside and a nucleotide?
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Ask Avogadro for the adenosine molecule (sequence Fileà importà Fetch by chemical name), for a nucleoside, and build the corresponding nucleotide.