TEAS, Digestive Organ Production of Zymogens, Enzymes, and Hormones and Functions

Gastric Lipase

A small amount of lipase, called gastric lipase, is made by cells in your stomach. This enzyme specifically digests butter fat in your food.

Additional Enzymes to Add Later

Although amylase, protease and lipase are the three main enzymes your body uses to digest food, many other specialized enzymes also help in the process. Cells that line your intestines make enzymes called maltase, sucrase and lactase, each able to convert a specific type of sugar into glucose. Similarly, special cells in your stomach secrete two other enzymes -- renin and gelatinase. Renin acts on proteins in milk, converting them into smaller molecules called peptides, which are then fully digested by pepsin. Gelatinase digests gelatin and collagen, two large proteins in meat, into moderately-sized compounds whose digestion is then completed by pepsin, trypsin and chymotrypsin, producing amino acids. (saccharides)

The three main digestive enzymes

Amylase breaks down carbohydrates into glucose Lipase breaks down fats into fatty acids and glycerol Protease breaks down protein into its smaller building blocks: amino acids

Liver Produces: Digestive Enzyme & No Hormones

Bile (Stored in Gall Bladder)

Salivary Amylase

Converts carbohydrates/starches into smaller carbohydrate molecules called maltose Released from salivary glands in the mouth

Stomach: Produces Digestive Enzymes & Hormones

Digestive Enzymes: -Gastric Lipase -Pepsinogen -HCl (Hydrochloric Acid pH 2) Hormones: -Ghrelin -Gastrin

Pancreas: Produces Digestive Enzymes and Hormones

Digestive Enzymes: -Pancreatic Juice (Bicarbonate, Lipase, Trypsinogen) -Proteases and Amylase Hormones: -Secretin -Somatostatin -Insulin -Glucagon

Mouth: Produces Digestive Enzymes & No Hormones

Digestive Enzymes: -Salivary Amylase -Salivary Lipase

Small Intestine: Produces Digestive Enzymes & Hormones

Digestive Enzymes: -Brush Border Enzymes (Proteases, Lactase, & Disaccharidases) Hormones: -Cholecystokinin -Somatostatin -Secretin -Motilin

Large Intestine: Produce no Digestive Enzymes or Hormones

Does not produce digestive enzymes or hormones but aids in Water reabsorption and acts asConduit for stool (double check)

Pancreatic Amylase

Injects via duct into small intestine to complete carbohydrate digestion (Assume it converts maltose) converts carbohydrates into glucose

Pancreatic Lipase

Most lipase in the digestive system is produced in the Pancreas. Pancreatic lipase acts in your small intestine. First, bile made in your liver and released into your intestine converts dietary fat into small fatty globules. Pancreatic lipase, also called steapsin, acts on these fat globules, converting them into fatty acids and glycerol, which are small, energy-dense molecules used by all your cells. Fatty acids and glycerol travel in blood and your lymph vessels to reach all parts of your body.

The three main proteases

Pepsin, trypsin and chymotrypsin

Pepsinogen

Pepsinogen, an inactive zymogen, is secreted into gastric juice from both mucous cells and chief cells. Once secreted, pepsinogen is activated by stomach acid into the active protease pepsin, which is largely responsible for the stomach's ability to initiate digestion of proteins

Trypsin vs Chymotrypsin

Trypsin, produced in an inactive form by the pancreas, is remarkably similar in chemical composition and in structure to the other chief pancreatic proteinase, chymotrypsin. Both enzymes also appear to have similar mechanisms of action; residues of histidine and serine are found in the active sites of both. The chief difference between the two molecules seems to be in their specificity, that is, each is active only against the peptide bonds in protein molecules that have carboxyl groups donated by certain amino acids. For trypsin these amino acids are arginine and lysine, for chymotrypsin they are tyrosine, phenylalanine, tryptophan, methionine, and leucine. Trypsin is the most discriminating of all the proteolytic enzymes in terms of the restricted number of chemical bonds that it will attack.

Trypsinogen

a zymogen (precursor) of trypsin, functions as storage of an inactive form of trypsin so that it may be kept in the pancreas and released in significant amount when required for protein digestion. It is released by the pancreas itself along with other enzymes... It is activated by enteropeptidase, which is found in the intestinal mucosa, to form trypsin. Once activated, the trypsin can activate more trypsinogen into trypsin. Trypsin cleaves the peptide bond on the carboxyl side of basic amino acids such as arginine and lysine.

Pepsin

breaks down proteins into polypeptides

Zymogens or Proenzymes

inactive precursor of an enzyme...A zymogen requires a biochemical change (such as a hydrolysis reaction revealing the active site, or changing the configuration to reveal the active site) for it to become an active enzyme. The biochemical change usually occurs in Golgi bodies, where a specific part of the precursor enzyme is cleaved in order to activate it. The inactivating piece which is cleaved off can be a peptide unit, or can be independently folding domains comprising more than 100 residues. Although they limit the enzyme's ability, these n-terminal extensions of the enzyme or a "prosegment" often aid in the stabilizing and folding of the enzyme they inhibit. The pancreas secretes zymogens partly to prevent the enzymes from digesting proteins in the cells in which they are synthesised. Enzymes like pepsin are created in the form of pepsinogen, an inactive zymogen. Pepsinogen is activated when chief cells release it into the gastric acid, whose hydrochloric acid partially activates it. Another partially activated pepsinogen completes the activation by removing the peptide, turning the pepsinogen into pepsin. Accidental activation of zymogens can happen when the secretion duct in the pancreas is blocked by a gallstone resulting in acute pancreatitis. Another way that enzymes can exist in inactive forms and later be converted to active forms is by activating only when a cofactor, called a coenzyme, is bound. In this system, the inactive form (the apoenzyme) becomes the active form (the holoenzyme) when the coenzyme binds. Examples of zymogens: Angiotensinogen Trypsinogen Chymotrypsinogen Pepsinogen Most proteins in the coagulation system (for example, fibrinogen) Some of the proteins of the complement system Procaspases Pacifastin Proelastase Prolipase Procarboxypolypeptidases

Chymotrypsinogen

is a proteolytic enzyme and a precursor (zymogen) of the digestive enzyme chymotrypsin. It is a single polypetide chain consisting of 245 amino acid residues. It is synthesized in the acinar cells of the pancreas and stored inside membrane-bounded granules at the apex of the acinar cell. The cell is then stimulated by either a hormonal signal or a nerve impulse and the contents of the granules spill into a duct leading into the duodenum. Chymotrypsinogen must be inactive until it gets to the digestive tract. This prevents damage to the pancreas or any other organs. It is activated into its active form by another enzyme called trypsin.

Chymotrypsin

proteolytic, or protein-digesting, enzyme active that catalyzes the hydrolysis of proteins, degrading them into smaller molecules called peptides. Peptides are further split into free amino acids.

Trypsin

trypsin acts with the other proteinases to break down dietary protein molecules to their component peptides and amino acids, which is a necessary step in protein absorption, as proteins are generally too large to be absorbed through the lining of the small intestine. Trypsin is produced as the inactive zymogen trypsinogen in the pancreas.