Keywords: Nucleotides.gif Each nucleic acid contains many building blocks called nucleotides The nucleotides have a distinctive structure composed of three components that held together by covalent bond a nitrogen-containing base cytosine thymine acenine guanine a 5-carbon sugar - ribose or deoxyribose a phosphate group en wikibooks Adrignola CommonsHelper 2008-11-09 Calibuon wikibooks en b English Wikibooks Calibuon Original upload log page en wikibooks Nucleotides gif 2008-11-09 03 19 Calibuon 429×180× 3765 bytes <nowiki></nowiki> Nucleotides |