Question

Carboxypeptidases belong to the group

• A. Exopeptidases
• B. Endopeptidases
• C. Cystine proteases
• D. Serine proteases

Hint:

Ends vs. Middle:
- Exopeptidase (like Carboxypeptidase, Aminopeptidase) = Snips the ends.
- Endopeptidase (like Trypsin, Pepsin) = Snips the middle.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the biochemical classification of carboxypeptidases, which are important digestive enzymes found in the intestinal tract of fishes and other animals.
Detailed Explanation:

• Peptidase Classification: Proteolytic enzymes (proteases) are divided into two main categories based on where they cleave the peptide chain:
• Endopeptidases: Cleave internal peptide bonds within the protein molecule (e.g., Pepsin, Trypsin, Chymotrypsin).

• Exopeptidases: Cleave one amino acid at a time from the ends of the polypeptide chain.

• Carboxypeptidase Role: As the name implies, these enzymes specifically target the C-terminal (carboxyl end) of a protein and remove the terminal amino acid. Because they act on the "exterior" end of the chain, they are classified as Exopeptidases.

• Origin: They are produced as inactive zymogens (pro-carboxypeptidases) in the pancreas and are activated in the intestine.

Step 2: Final Answer:
Carboxypeptidases are categorized as exopeptidases.