Question

Zinc containing enzyme(s) is/are

• A. carboxypeptidase
• B. hydrogenase
• C. carbonic anhydrase
• D. urease

Answer 1

The Correct Option is A, C

The question asks us to identify which enzymes contain zinc. Let's evaluate each of the given options based on their known composition and structure:

1. Carboxypeptidase: This is an enzyme that contains zinc. It is a metalloprotease, meaning it requires a metal ion, in this case, zinc, for its enzymatic activity. The zinc ion in carboxypeptidase plays a crucial role in its mechanism by stabilizing a water molecule, which is involved in the hydrolysis of peptide bonds.
2. Hydrogenase: This enzyme does not typically contain zinc. Hydrogenases are enzymes that catalyze the reversible oxidation of hydrogen gas. They often contain metals such as nickel and iron in their active sites.
3. Carbonic Anhydrase: Like carboxypeptidase, carbonic anhydrase is another zinc-containing enzyme. It catalyzes the conversion of carbon dioxide and water to bicarbonate and protons and is essential in maintaining acid-base balance in the blood and tissues. Zinc is vital for its catalytic function.
4. Urease: This enzyme does not contain zinc; it actually contains nickel in its active site. Urease catalyzes the hydrolysis of urea into carbon dioxide and ammonia.

Thus, the correct answers are carboxypeptidase and carbonic anhydrase, both of which are known as zinc metalloenzymes.