Question

For its activity, carboxypeptidase requires-
A. Iron
B. Niacin
C. Copper
D. Zinc

Answer 1

Hint: Enzymes are basically proteins that act as catalysts. The main function of a catalyst is to accelerate the rate of chemical reactions. The molecules upon which enzymes first attack are called substrates, and then they convert the substrates into different molecules which are termed as products.

Complete answer:
• A carboxypeptidase is a protease chemical that hydrolyzes a peptide bond at the carboxy-terminal of a protein or peptide.
• It is a decent delineation of the incited fit hypothesis because the dynamic site changes considerably when the substrate ties.
• As the protein substrate ties to carboxypeptidase, the dynamic site surrounds it. Hydrolysis of the peptide bond is well on the way to happen if the terminal buildup has a massive hydrocarbon side chain.
• A zinc particle (Zn$^{2+}$) is firmly bound close to the dynamic site and aids catalysis. Three hydrogen holding and electrostatic communications are basic for the compound to perceive the terminal amino corrosive in the peptide chain.
• The middle is settled by associations with Zn$^{2+}$, the carboxypeptidase particle. The last advance is a proton move and cleavage of the peptide bond.
• This whole cycle requires significant versatility of the carboxypeptidase A protein itself.

Thus, carboxypeptidase requires zinc for its action, and not iron, niacin, or copper.
Hence, the correct answer is option (D).

Note: The first carboxypeptidases examined were those engaged with the processing of food. Be that as it may, the vast majority of the known carboxypeptidases are not engaged with catabolism; they help to develop proteins or control natural cycles. For instance, the biosynthesis of neuroendocrine peptides, for example, insulin requires a carboxypeptidase. Carboxypeptidases additionally work in blood coagulating, development factor creation, wound mending, propagation, and numerous different cycles.