Enzymes in the small intestine and their functions

By | 28.12.2017

Please forward this error screen to 162. Please forward this error screen to 96. Enzymes in the small intestine and their functions pancreas plays multiple roles in digestion, absorption, metabolism and storage of nutrients. The acinar cells of the pancreas produces enzymes for digesting food in the gut. It is then released into the ductules which empty the contents into the pancreatic duct.

These chemical catalysts are inactive until it enters the lumen of the small intestine, where it is activated by the acidity of the stomach contents or other digestive enzymes. Various enzymes act on different types of food. The pancreatic enzymes chemically break down the food into simpler substances which can be digested further by other enzymes or absorbed through the lining of the gut. The actions and regulation of these catalysts are discussed further below. It also influences the storage of excess nutrients. Insulin increases the uptake of glucose by the cells thereby reducing the blood glucose levels and promoting storage of excess glucose. Glucagon mobilizes glucose from the glucose stores and increases the blood glucose levels.

Both these hormones can influence nutrient digestion and absorption to some extent. D cells in the lining of the gastrointestinal tract. Somastatin therefore also influences at what temperature are food enzymes destroyed. These hormones also play a role in controlling the secretion of digestive enzymes.

However, it is the enzymes itself that function in the small intestine to break down foods into simpler nutrients so that it can be easily absorbed into the blood stream. Along with water, bicarbonates ions and mucus, the total exocrine secretion from the pancreas is approximately 1 liter per day. These digestive enzymes from the pancreas are secreted by the acini within the gland and this empties into the pancreatic duct. From here, it joins the common bile duct and empties into the duodenum of the small intestine. Apart from the enzymes for digestion, the pancreas also secretes bicarbonate ions and water. These compounds are secreted by the epithelial cells that line the pancreatic duct and help to neutralize the gastric acid from the stomach in addition to transporting the pancreatic enzymes out of the pancreas. There are three pancreatic enzymes for the digestion of proteins within the food in the small intestine. Of these, trypsin is the most abundant. The pancreas do not secrete these enzymes in it active form as this may result in digestion of the pancreas itself.

Once in the lumen of the duodenum, these enzymes are activated. Trypsinogen, which is the most abundant of the three pancreatic enzymes, is activated by the presence of enterokinase which is an enzyme secreted by the lining of the small intestine. Further trypsinogen is also activated by the presence of trypsin in the gut. Chymotrypsin, procarboxypolypeptidase and proelastase are in turn activated by trypsin. The pancreas also has other protective mechanisms to ensure that these enzymes do not damage it. Trypsin and chymotrypsin breaks down protein into peptides. Carboxypolypetidase in turn breaks down some peptides into individual amino acids but it is the peptidases secreted by the enterocytes of the small intestine that digest the rest. Elastase is more specific and digests collagen, particularly the elastin that holds fibers in meat together. Pancreatic amylase hydrolyzes most carbohydrates into disaccharides and trisaccharides.