Catalytic activity is _________ when __________ is removed from the enzyme which testifies that they play crucial role in the catalytic activity of the enzyme.

Step-by-step solution

Enzymes are proteinaceous in nature. Some Enzymes also contain non-protein part known as Co-factors. These factors are attached to the Enzymes to enhanced their catalytic activity. The protein part of Enzyme is known as Apoenzyme. Hence Apoenzyme (Protein part) + Co-factors (Non protein part) = Holoenzyme (Whole Enzyme). As the co-factors are bound to enzymes, the removal of these factors affects the overall activity of Enzymes too.