Library · Physiology
Pancreatic enzymes
Make it clearer
The pancreas makes the enzymes that break food apart: an amylase for starches, a lipase for fats and, for proteins, four molecules with long names that arrive switched off: trypsinogen, chymotrypsinogen, procarboxypeptidase and proelastase.
Arriving switched off is the important part. Enzymes that cut proteins cannot tell the meat in a meal from the pancreas itself, so the organ never releases them active. They are scissors that travel with the safety on and open only on arrival. When that safety fails and they switch on inside, the pancreas digests itself: that is pancreatitis.
The safety comes off in the duodenum, the first portion of the intestine. There a duodenal enzyme, enterokinase, converts trypsinogen into trypsin, and trypsin goes on to activate all the rest.
They work best at a pH of 6 to 7, less acidic than the stomach, and the bicarbonate the pancreas itself sends out keeps it there.
In brief
The pancreas makes amylase for starch, lipase for fat and the precursors trypsinogen, chymotrypsinogen, procarboxypeptidase and proelastase.
It does not release the peptidases in active form: if it did, it could digest itself, which is what happens in pancreatitis.
Scissors that travel with the safety on and open only on arrival.
In the duodenum, enterokinase converts trypsinogen into trypsin, and trypsin activates the rest.
They work best at the intestine's pH of 6 to 7, more alkaline than the stomach thanks to pancreatic bicarbonate.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingPhysiology, Digestion, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated