An enzyme in pancreatic juice that breaks down protein molecules is

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

Answer: (B)

Proteins are digested by proteases, a group of enzymes that cut peptide bonds in protein molecules. In pancreatic juice, the specific enzyme that does this job is trypsin, a protease secreted by the pancreas (as trypsinogen and activated in the intestine). Once active, it cleaves peptide bonds, producing smaller peptides that are further digested downstream. Lipase targets fats, amylase targets carbohydrates, and protease is the general class name for protein-digesting enzymes, with trypsin being the particular pancreatic protease responsible for protein breakdown.