The d-and L-forms of amino acids are named in reference to the absolute configuration of D-and L glyceraldehydes(whose structure was originally assumed and confirmed by x-ray crystallography later). ICHO CHO HO-C-H H-C-OH BCHOOH CHOH L-Glyceraldehyde D-Glyceraldehyde CoO CoO H—C=NH3 CH3 CH3 L-Alanine D-Alanine Lined up by similarity: chiral to chiral, Coo to CHOLined up by similarity: chiral to chiral, COO to CHO The D- and L-forms of amino acids are named in reference to the absolute configuration of D- and L￾glyceraldehydes (whose structure was originally assumed and confirmed by X-ray crystallography later)