Question
Chymotrypsin cleaves carbonyl terminal of:
| A. |
Phenylalanine |
| B. |
Tryptophan |
| C. |
Tyrosine |
| D. |
All |
|
Correct Answer » D Explanation |
 |
Explanation:
– Chymotrypsin is a pancreatic serine protease that cleaves peptide bonds.
– It targets the carbonyl (C-terminal) side of aromatic amino acids.
– These include phenylalanine, tyrosine, and tryptophan.
– The enzyme prefers bulky, hydrophobic side chains, so all three are cleaved.
– Hence, option D (“All of the above”) is correct.
Why other options are incorrect:
– A: Phenylalanine alone is not the only target; others also cleaved.
– B: Tryptophan is one among multiple aromatic amino acids cleaved.
– C: Tyrosine is part of the group targeted, not exclusive.
High‑Yield:
– Function: Chymotrypsin aids protein digestion in the pancreas.
– Specificity: Cleaves peptide bonds at carbonyl side of bulky aromatic residues.
– Mechanism: Active site serine attacks peptide bond carbonyl carbon.
– Clinical: Deficiency/inhibition impairs digestion; used to study proteins in labs.
