Metal Ions as Enzyme Cofactors — NEET Biology
✅ Asked in NEET 2024A number of enzymes require metal ions for their activity which form coordination bonds with side chains at the active site and at the same time form one or more coordination bonds with the substrate, e.g., zinc is a cofactor for the proteolytic enzyme carboxypeptidase.
NTA tests your understanding that certain enzymes require metal ions (like zinc) as cofactors to function. These metal ions form coordination bonds with the enzyme's active site and with the substrate molecule itself, enabling catalysis. Students often mistake cofactors for coenzymes (which are organic) or forget that metal ions directly participate in substrate binding and catalysis. Remember: zinc in carboxypeptidase is a classic example—it's not just present in the enzyme but actively coordinates with both the protein structure and the substrate to facilitate protein digestion. This concept appears frequently because it bridges enzyme structure, metal chemistry, and biochemical function.
The cofactor of the enzyme carboxypeptidase is:
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.