( 1 ) the synthesis and removal of phenylalanine ammonia-lyase ( ec 4.3.1.5 ) in illuminated discs of potato ( solanum tuberosum cv king edward ) tuber tissue has been investigated by density labelling with deuterium ( 2h ) from deuterium oxide ( 2h2o ) followed by centrifugation to equilibrium in a csc1 density gradient .
C0011744
deuterium
C0011745
deuterium oxide