The Enzymes of Human Digestion There are always others, but these are the ones I’m making you memorize

Ingestion, Digestion and Respiration Ingestion is the taking in of food or nutrients Digestion is the process of breaking down large food particles into their smaller sub-units which can be absorbed into individual cells Respiration is the process of combining energy storage molecules (usually sugar) with Oxygen (burning) to release energy. The energy is usually stored in ATP molecules

Mouth Food is mechanically chewed, water and saliva dissolve inorganic salts and minerals. The enzyme amylase begins to break down starches into smaller saccharides Food than passes through esophagus to stomach

stomach -mechanical churning and mixing with acid further breaks down food and begins to dissolve some non-water soluble molecules. The enzyme Pepsin begins to break down proteins into amino acids Food passes into the intestine, where more enzymes from glands and other organs will finish the job

Liver and Gall bladder Bile, produced by the liver and stored in the gall bladder, secretes into the small intestine and begins to break down fats and lipids. (Bile works better in acid)

Pancreas The pancreas secretes; trypsins, elastase and some peptidase to help break the peptide bonds separating proteins into amino acids. Also the pancreas secretes more amylase to finish breaking down carbohydrates into mono-saccariades. As well it secretes buffer solutions to neutralize stomach acids

Intestinal glands Glands in the intestines also secrete peptidase enzymes to finish breaking down proteins. The digested sub-units are now absorbed through folded membranes of the small intestine. Undigested material continues into the large intestine, where it encounters a helper bacterium

Digestive organs Digestive enzymes digest proteins trypsin, elastase, peptidase digest starch Amylase Digest fats bile

E-coli E-coli bacterium in the large intestine further digest food particles anaerobically using their own set of enzymes, and excrete vitamin K as a by-product. * most strains of E-Coli are not disease causing, there’s a few disease causing that give the rest a bad reputation.

Assignment Try concept check #1 page 637 #2,3 page 642 You should be able to match enzyme to macromolecule it digests, or organ where it is produced or stored, for upcoming test.