DISCUSSION The intention of this experiment is to observe how fluctuations of pH in the small intestine can affect the enzymatic activity of trypsin. Trypsin is a serine protease that is secreted by the pancreas into the duodenum in an inactive form, trypsinogen (Weaver 2012 p.1). In its active form as trypsin, the enzyme contributes to food digestion by hydrolyzing proteins into peptides in the small intestine (Weaver 2012 p. 75). In this experiment the substrate, Nα-benzoyl-DL-arginine 4-nitroanilide hydrochloride (BAPA) undergoes hydrolysis catalyzed by trypsin and produces p-nitroaniline. The optimal pH range of trypsin is 7.5 to 8.5, which similar to the basic environment of the small intestines (Promega 2014). Introduction to an acidic