Biology - Biomolecules Question with Solution | TestHub

According to NCERT Biology, cofactors are non-protein constituents bound to the enzyme to make it catalytically active.

There are three kinds of cofactors: prosthetic groups, co-enzymes, and metal ions.

Prosthetic groups are organic compounds that are distinguished from other cofactors in that they are tightly bound to the apoenzyme (the protein part of the enzyme).

Co-enzymes are also organic compounds, but their association with the apoenzyme is only transient.

Therefore, the organic compounds tightly attached to the protein part of an enzyme are called prosthetic groups.

Answer: prosthetic groups