Question

In a protein, trypsin catalyzes the hydrolysis of peptide bonds with carbonyl group contributed by

• A. glutamine
• B. asparagine
• C. lysine
• D. arginine

Hint:

Trypsin cleaves peptide bonds specifically after the basic amino acids lysine and arginine, unless followed by proline.

Answer 1

The Correct Option is C, D

Step 1: What trypsin prefers.
Trypsin is a serine protease that cuts a protein chain on the carboxyl side of certain residues.

Step 2: Name those residues.
It acts after the basic amino acids lysine and arginine, whose positive side chains fit the enzyme's pocket.

Step 3: Read the carbonyl clue.
Saying the carbonyl group is contributed by a residue means the cut comes right after that residue. So lysine and arginine are the answers.

Step 4: Drop the others.
Glutamine and asparagine are neutral and polar, not the basic targets trypsin needs, so they are wrong.

Step 5: Answer.
\[ \boxed{C,\ D} \]