Which enzyme is a pancreatic protease that cleaves after basic residues?

Prepare for your Anatomy and Physiology II Exam with our comprehensive exam resources. Utilize flashcards, multiple choice questions with hints, and detailed explanations. Boost your readiness for success!

Multiple Choice

Which enzyme is a pancreatic protease that cleaves after basic residues?

Proteases in the pancreas include enzymes that cut peptide bonds in different patterns. The one that cleaves after basic (positively charged) residues is trypsin. It is produced as an inactive zymogen and activated in the intestinal lumen. Trypsin has a negatively charged pocket in its S1 site that forms ionic interactions with the side chains of lysine and arginine, so it preferentially cleaves on the carboxyl side of these basic residues. Chymotrypsin, by contrast, favors bulky hydrophobic residues like phenylalanine, tyrosine, and tryptophan. Elastase targets small neutral residues such as glycine and alanine. Carboxypeptidase acts at the C-terminus (exopeptidase activity), removing amino acids one by one rather than cutting after a residue within the chain.

Proteases in the pancreas include enzymes that cut peptide bonds in different patterns. The one that cleaves after basic (positively charged) residues is trypsin. It is produced as an inactive zymogen and activated in the intestinal lumen. Trypsin has a negatively charged pocket in its S1 site that forms ionic interactions with the side chains of lysine and arginine, so it preferentially cleaves on the carboxyl side of these basic residues.

Chymotrypsin, by contrast, favors bulky hydrophobic residues like phenylalanine, tyrosine, and tryptophan. Elastase targets small neutral residues such as glycine and alanine. Carboxypeptidase acts at the C-terminus (exopeptidase activity), removing amino acids one by one rather than cutting after a residue within the chain.

More practice questions