l-cysteine molecular structure 3d, flat model, cysteine e920, structural chemical formula view from a microscope

lcysteine cysteine cys e920 semiessential proteinogenic amino acid nucleophile ugu ugc molecule molecular structure chemical formula c3h7no2s 3d model atom chemistry science carbon biochemistry skeletal hydrogen organic oxygen atomic biology medical structural medicine laboratory pharmacy physical drug additive cystine bond essential scientific health nitrogen medication