digestive enzymes

Examples of digestive enzymes in the following topics:

• Pancreatic Juice

  • Pancreatic fluid contains digestive enzymes that help to further break down the carbohydrates, proteins, and lipids in the chyme.
  • The pancreas is a glandular organ in the digestive system and endocrine system of vertebrates.
  • It is both an endocrine gland that produces several important hormones—including insulin, glucagon, somatostatin, and pancreatic polypeptide—and a digestive organ that secretes pancreatic juice that has digestive enzymes that assist the absorption of nutrients and digestion in the small intestine.
  • These enzymes help to further break down the carbohydrates, proteins, and lipids in the chyme.
  • Because the pancreas is a sort of storage depot for digestive enzymes, injury to the pancreas is potentially fatal.

• Digestive Processes of the Small Intestine

  • The small intestine uses different enzymes and processes to digest proteins, lipids, and carbohydrates.
  • The small intestine is where most chemical digestion takes place.
  • Most of the digestive enzymes in the small intestine are secreted by the pancreas and enter the small intestine via the pancreatic duct.
  • Brush border enzymes take over from there.
  • Other brush border enzymes are maltase, sucrase, and lactase.

• Chemical Digestion of Carbohydrates, Proteins, Lipids, and Nucleic Acids

  • Chemical breakdown of macromolecules contained in food is completed by various enzymes produced in the digestive system.
  • Protein digestion occurs in the stomach and the duodenum through the action of three primary enzymes: pepsin, secreted by the stomach, and trypsin and chymotrypsin, secreted by the pancreas.
  • These enzymes break down food proteins into polypeptides, which are then broken down by various exopeptidases and dipeptidases into amino acids.
  • The digestive enzymes, however, are secreted mainly as their inactive precursors, the zymogens.
  • Sucrase is an enzyme that breaks down disaccharide sucrose, commonly known as table sugar, cane sugar, or beet sugar.

• Histology of the Pancreas

  • The pancreas serves digestive and endocrine functions, and it is composed of two types of tissue: islets of Langerhans and acini.
  • The pancreas is a glandular organ in the digestive system and endocrine system of vertebrates.
  • It is both an endocrine gland that produces several important hormones—including insulin, glucagon, somatostatin, and pancreatic polypeptide—as well as a digestive organ that secretes pancreatic juice that contain digestive enzymes to assist the absorption of nutrients and digestion in the small intestine.
  • These enzymes also help to further break down the carbohydrates, proteins, and lipids in the chyme.
  • Acinar cells belong to the exocrine pancreas and secrete digestive enzymes into the gut via a system of ducts.

• Pancreas

  • As a digestive organ, the pancreas secretes pancreatic juice that contains digestive enzymes that assist the absorption of nutrients and digestion in the small intestine.
  • The exocrine function of the pancreas is essential for digestion as it produces many of the enzymes that break down the protein, carbohydrates, and fats in digestible foods.
  • The cells are filled with secretory granules containing the inactivated digestive enzymes, mainly trypsinogen, chymotrypsinogen, pancreatic lipase, and amylase, that are secreted into the lumen of the acini.
  • The pancreas synthesizes its enzymes in the inactive form, known as zymogens, to avoid digesting itself.
  • The enzymes are activated once they reach the small intestine.

• Pancreatitis

  • Pancreatitis, or inflammation of the pancreas, occurs when the pancreatic enzymes that digest food are activated inside the pancreas.
  • The pancreas plays an important role in the regulation of blood glucose levels through the production of hormones, as well as in digestion, through the production of enzymes that break down food in the small intestine.
  • Pancreatitis occurs when the pancreatic enzymes that digest food are activated in the pancreas instead of the small intestine, causing the pancreas to digest, or break down, its own tissue .
  • Unexplained weight loss may occur from decreased amounts of pancreatic enzymes hindering digestion.
  • Mild pancreatitis treatment typically involves restriction of foods to avoid production of digestive enzymes, and administration of opiate-based painkillers.

• Hormones of the Digestive System

  • There are five main hormones that aid and regulate the digestive system in mammals.
  • There are five main hormones that aid in regulation of the digestive system in mammals.
  • Gastrin is in the stomach and stimulates the gastric glands to secrete pepsinogen (an inactive form of the enzyme pepsin) and hydrochloric acid.
  • Cholecystokinin (CCK) is in the duodenum and stimulates the release of digestive enzymes in the pancreas and stimulates the emptying of bile in the gall bladder.

• Associated Organs

  • The pancreas produces enzymes that help digest proteins, fats, and carbohydrates, the liver produces bile that helps the body absorb fat, and the gallbladder stores the bile until it is needed.
  • The exocrine function of the pancreas is essential for digestion as the produces many of the enzymes that break down protein, carbohydrates, and fats in digestible foods.
  • The cells are filled with secretory granules containing the inactivated digestive enzymes, mainly trypsinogen, chymotrypsinogen, pancreatic lipase, and amylase, that are secreted into the lumen of the acini.
  • The pancreas synthesizes its enzymes in the inactive form, known as zymogens, to avoid digesting itself.
  • The enzymes are activated once they reach the small intestine.

• Processes and Functions of the Digestive System

  • Here is a look at the importance of two main functions of the digestive system: digestion and absorption.
  • Chemical digestion: Several different enzymes break down macromolecules into smaller molecules that can be absorbed.
  • Digestion begins in the mouth.
  • Amylase, the digestive enzyme found in saliva, starts to break down starch into simple sugars before the food even leaves the mouth.
  • The stomach is a muscular bag that maneuvers food particles, mixing highly acidic gastric juice and powerful digestive enzymes with the chyme to prepare for nutrient absorption in the small intestine.

• Mechanisms of Chemical Digestion

  • Chemical digestion is the process of breakdown of large macronutrients into smaller molecules by enzyme-mediated hydrolysis.
  • The proteolytic enzymes are all secreted in an inactive form, to prevent auto-digestion, and are activated in the lumen of the gut: by HCl in the case of the stomach pepsinogen; by enteropeptidase and trypsin in the case of the pancreatic enzymes.
  • Final digestion takes place by small intestine enzymes embedded in the brush border of the small intestine.
  • The enzymes are divided into endo- and exo-peptidases.
  • Stomach pepsin digests about 20% of the proteins, the rest is digested by pancreatic and small intestine enzymes.