Elementary plant Biochemistry and Biotechnology (2+1)

Fischer’s lock and key theory (Rigid template model)

• During 1890, Emil Fischer proposed this theory.
• According to this, the active site possesses a unique conformation which is complementary to the structure of the substrate thus enabling the two molecules to fit together in much the same way as a key fits into a lock .
• An unfortunate feature of this model is the implied rigidity of the catalytic site.