Aim and Background. Per o xi d ases a re o n e o f t he m o st i m p o rta n t enz y mes that p artici pa t es in many p h y s i o lo g i c al p rocesses in p l a n ts. Peroxidases are heme containing proteins that utilize H₂O₂ in the oxidation of various organic and inorganic substrates. In this research, the activity of peroxidase, was investigated in Crocus sativus L. co r m s extracts . The activity of peroxidase was studied with different c on c e ntr at i o n o f H ₂ O ₂ and pH measurement .

Materials and Methods. In this study t h e pl a nt cor m s were p r epa r e d in Ju l y as dor m ant stage and Novamber as waking stage . C o r m s were us e d as t h e enz y me e x trac t i on sou r ce and w as u s e d f o r f u rt h e r st ud y .

Results. T h e re s ul t s s h o w e d t h at t h e o pti m u m p H o f e n z y m e activity i n dor m an c y s ta g e i s on e un i t higher t h a n th e w a k i ng . T he r e sul t s sug g ested t h at in c r e a si n g c on c e ntr at i o n o f H ₂ O ₂ up to t h e 8 0 mM i n cr e as e s the enz y ma t ic acti v ity a nd higher c oncentra ti ons of H ₂ O ₂ de c r ea s e the pe r oxida s e act i vity .

Conclusion. According t o th e k i n e ti cs r e s ults , i t se e m s t h at at le a s t tw o is o f or m s o f t h e p e r o x i d a s es ex i s t i n s a f fr on co r m s a n d s o ea c h i s o f or m c ould t a k e p a r t i n so m e dif f ere n t p r oc e s s es i n g r o w t h and d e v e l o p m ent.