Editing Serine (section)

== Occurrence ==
[[File:Betain-Serin.png|class=skin-invert-image|thumb|left|250px|<small>L</small>-Serine (left) and <small>D</small>-serine (right) in zwitterionic form at neutral pH]]
This compound is one of the [[proteinogenic amino acid]]s. Only the <small>L</small>-[[stereoisomer]] appears naturally in proteins. It is [[non-essential amino acid|not essential]] to the human diet, since it is synthesized in the body from other [[metabolites]], including [[glycine]]. Serine was first obtained from [[silk]] protein, a particularly rich source, in 1865 by Emil Cramer.<ref>{{cite journal |last1=Cramer |first1=Emil |title=Ueber die Bestandtheile der Seide |journal=Journal für praktische Chemie |date=1865 |volume=96 |pages=76–98 |url=https://babel.hathitrust.org/cgi/pt?id=hvd.hxgq72&view=1up&seq=94 |trans-title=On the constituents of silk |language=German}}  Serine is named on p. 93:  ''"Ich werde den in Frage stehenden Körper unter dem Namen Serin beschreiben."'' (I will describe the body [i.e., substance] in question by the name "serine".)</ref> Its name is derived from the [[Latin]] for silk, ''[[wikt:sericum|sericum]]''.  Serine's structure was established in 1902.<ref>{{cite journal |last1=Fischer |first1=Emil |last2=Leuchs |first2=Hermann |title=Synthese des Serins, der ''l''-Glucosaminsäure und anderer Oxyaminosäuren |journal=Berichte der Deutschen Chemischen Gesellschaft |date=1902 |volume=35 |issue=3 |pages=3787–3805 |doi=10.1002/cber.190203503213 |url=https://babel.hathitrust.org/cgi/pt?id=hvd.cl1i27&view=1up&seq=1255 |trans-title=Synthesis of serine, of ''l''-glucosaminic acid, and other oxyamino acids |language=de}}</ref><ref>{{cite encyclopedia|title=Serine|url=http://www.encyclopedia.com/topic/serine.aspx|encyclopedia=The Columbia Encyclopedia 6th ed.|publisher=encyclopedia.com|access-date=22 October 2012}}</ref>