Compare with nucleotide . A nucleotide base bound to a five-carbon sugar. Compare with nucleoside . A molecule which is a basic building block of nucleic acids and which plays a key role in energy transfer in biochemical reactions. A heterocyclic nitrogen-containing base that is a constituent of nucleotides .
Examples are adenine, guanine, thymine, uracil, and cytosine.
Compare with atomic nucleus , nuclide and element symbol . A symbol for an nuclide that contains the mass number as a leading superscript and the atomic number as a leading subscript. For ions, the ionic charge is given as a trailing superscript. The atomic number is sometimes omitted from nuclide symbols. Compare with atomic nucleus and nuclide symbol .