Which enzyme in pancreatic juice breaks down proteins?

• A. Lipase
• B. Amylase
• C. Protease
• D. Tryspin

Answer: (D)

Pancreatic juice uses proteolytic enzymes to digest proteins. A key enzyme in this mix is trypsin, a protease that reaches the small intestine in its active form and cleaves peptide bonds on the carboxyl side of lysine and arginine residues. This proteolysis initiates protein breakdown, and other pancreatic proteases like chymotrypsin and carboxypeptidases continue the process. Lipase targets fats and amylase targets starches, so those aren’t involved in protein digestion. While “protease” is a general category, the most specific enzyme in pancreatic juice for breaking down proteins is trypsin, which is why that option fits best.