Carbohydrate Absorption TBL-2 PDF

* Carbohydrate absorption > Principle sites - mouth and intestinal lumen -fast Process -done by glycoside hydrolases (glycosidases...

* Carbohydrate absorption > Principle sites - mouth and intestinal lumen -fast Process -done by glycoside hydrolases (glycosidases - break glycosidic bond in the Carbohydrate > Enzymes involved -Endoglycosidases soligosaccharides > Act on Polysaccharides , Break them into small units. > Disaccharidases Hisaccharides > absorbable form of > Target disaccharides , to produce monosaccharides Sugar in > Final Products -Glucose > Galactose > End Products of Carbohydrate digestion and are > Fructose absorbed in the enterocytes in the small intestine. * stages of carbohydrate digestion > Salivary x-amylase > Acts briefly in the mouth during chewing -Targeting > Amylose · Starch , Amylopectin + glycogen > break x (1-4) bonds > cannot break < (1->6) bonds found in branched molecules like > Products > Amylopectin > - Dextrins - short chains of glucose -glycogen > - Disaccharides--bcz -Amylase can't break it  > Digestion half temporarily in the stomach due to high acidity which inactivate salivary x-amylase = Pancreatic X-amylase > - As the stomach content enter the small intestine , bicarbonate will neutralize the acidity > -> So the Pancreatic a amylase will work - Intestinal Disaccharidases > In the duodinum and Jejunum > - final steps of digestion at the brush - Disaccharidases border of the mucosal living > icomaltase- > cleaves x (16) bond in isomaltose - > Producing glucose ↳ it also hydrolyze most maltose > maltase (l-y) bond -> cleases a in maltose and maltotriose >sucrase--a (l-2) bond in sucrose Produce glucose I Producing glucose + fructose > Lactaje (B-galactosidase) > B(1-y) bond in lactose - Produce galactose and glucose >Trehalage- &(l-1) - bonds in trehalose Produce glucose disaccharide - foundin mushroom and fungi > Intestinal absorption of monosaccharides -in the upper jejunum > each MS has diff mechanism. - glucose and galactose > - go into cell by secondary Active transport by SGT-2. * Nat gradient maintained by Nat/k + Pump > Fructose-> go into cell by Glut-3 - needed no energy or Nat > All monosaccharides - related to intestine ↳ exit enterocytes into the Portal circulation by GluT- then to blood blood Stream Dietary Protein digestion * < most dietary Proteins consumed as Protein (70 +oog/day) , b the Protein is too large to be directly absorbed so it will be brocken down , > dipeptides - intostripeptides - then absorbed. = Amino acids ↳ sources for enzymes - Digestion by Gastric Secretion · Protein digestion begins in the stomach with gastric Juice which contain - HC- Secreted by Parietal cell > PH = z - 3 - denature the Protein - easy digestion - doesn't directly digest the Protein it - kills come ingested bacteria zymogen. Pepsinogen Y < Pepsin - > Acid Stable enzyme released by chief cell-inactive > - Activated in the acid environment -cleare Polypeptide-release amino acids (free > - Digestion by Pancreatic enzymes activated by cholecystokinin > - > In the small intestine > - Pancreatic Proteases further break down Polypeptides oligopeptides this - > requires neutralized PH from bicarbonate secretion in response to secretin -Enzyme specificity > Each Pancreatic Protease targets Specific R-group of A A. in Peptides e -. g.- trypsin- break at 70 ofne C  · 2-zymogen release and Activation -Pancreatic enzymes release as inactive zymogens and activated enteropeptidase (enterokinase) in the by brush border of intestinal cell > - contesting trypsinogen--trypsin ↳ activate other Pancreatic zymogens creating cascade effect. - - Digestion of oligopeptides by SI enzymes -intestinal cells The enterocytes contain Aminopeptidase > exopeptidase - cleaves N-terminal AA. from Oligosaccharides to Produce small Peptides and free A N. - Amino Acid and small Peptide absorption : 3 - Absorption Abnormalities