Discuss the response of the pancreas (enzyme secretion) upon exposure to diets differing in the amounts of protein, fat, and carbohydrate. What is the most likely explanation for the observation that a person may experience "upset digestion" upon changing the diet? Why isn't the pancreas damaged by its own digestive enzymes?

Answer 1

Enzyme activity changes proportionately in response to the amounts of carbohydrate, fat, and protein in the diet. If a person has been eating mostly carbohydrates, the pancreas makes and secretes mostly carbohydrases; if the person's diet has been high in fat, the pancreas produces more lipases; and so forth. Hormones from the GI tract, secreted in response to meals, keep the pancreas informed as to its digestive tasks. The day or two lag between the time a person's diet changes dramatically and the time digestion of the new diet becomes efficient explains why dietary changes can "upset digestion" and should be made gradually. The pancreas protects itself from harm by producing an inactive form of the enzymes (zymogens). It releases these proteins into the small intestine, where they are activated to become enzymes.