Biosynthesis of cysteine from homocysteine and serine via cystathione intermediate
<a href="//commons.wikimedia.org/wiki/User:Nothingserious" title="User:Nothingserious">Nothingserious</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Nothingserious" title="User talk:Nothingserious"><span class="signature-talk">talk</span></a>)
David E. Volk at <a rel="nofollow" class="external text" href="http://en.citizendium.org/wiki/Image:Cysteine_Biosynthesis_DEVolk.png">Citizendium</a>