NEETBotanyBiomolecules (B)
Read the following statements regarding enzyme cofactors and choose the incorrect statement.
Options
- AZinc forms coordination bonds with side chains at the active site of the proteolytic enzyme carboxypeptidase.
- BCoenzymes are organic compounds whose association with the apoenzyme is tightly bound and permanent.
- CHaem is the prosthetic group in peroxidase and catalase, which catalyse the breakdown of hydrogen peroxide.
- DThe essential chemical components of many coenzymes are vitamins, such as niacin in NAD and NADP.
Correct answer
B. Coenzymes are organic compounds whose association with the apoenzyme is tightly bound and permanent.
Step-by-step solution
The statement in option 2 is incorrect. Coenzymes are organic compounds, but their association with the apoenzyme is only transient, usually occurring during the course of catalysis. Prosthetic groups, on the other hand, are tightly bound to the apoenzyme. The other statements are correct: Zinc is a metal ion cofactor for carboxypeptidase, haem is a tightly bound prosthetic group in peroxidase and catalase, and vitamins like niacin form the essential chemical components of coenzymes like NAD and NADP. Answer: Coenz