Overview Overview dietary carbohydrates include polysaccharides, disaccharides, and monosaccharides intestinal epithelial cells absorb only monosaccharides glucose, galactose, and fructose Digestion of dietary polysaccharides salivary secretions salivary α-amylase initiates digestion of polysaccharides in mouth digests interior α-1,4 glycosidic linkages, yielding 3 disaccharides α-limit dextrins, maltose, and maltotriose salivary α-amylase plays a minimal role in digestion of carbohydrates low pH of gastric contents quickly inactivates salivary α-amylase pancreatic secretions pancreatic juices are secreted into lumen of duodenum of small intestine pancreatic α-amylase initiates digestion of polysaccharides in the small intestines digests interior α-1,4 glycosidic linkages, yielding 3 disaccharides α-limit dextrins, maltose, and maltotriose intestinal mucosa intestinal brush border enzymes initiate digestion of disaccharides to monosaccharides α-dextrinase catalyzes α-limit dextrins → glucose maltase catalyzes maltose → glucose sucrase catalyzes maltotriose → glucose intestinal epithelial cells absorb glucose, a monosaccharide Digestion of dietary disaccharides dietary disaccharides include trehalose, lactose, and sucrose dietary disaccharides do not require α-amylase digestion intestinal brush border enzymes initiate digestion of disaccharides to monosaccharides trehalase catalyzes trehalose → glucose + glucose lactase catalyzes lactose → glucose + galactose sucrase catalyzes sucrose → glucose + fructose intestinal epithelial cells absorb glucose, galactose, and fructose, all monosaccharides
QUESTIONS 1 of 1 1 Previous Next (M1.GI.15.75) A 13-year-old boy presents to his physician for a routine visit. He states that he feels well and has no major complaints. On review of systems, he does note that he seems to have significant belly pain and increased flatulence whenever he eats any dairy products and thus has stopped consuming them. The pediatrician explains that he most likely has an enzyme deficiency. If a small bowel biopsy were to be performed on this patient, which of the following figures most accurate demonstrates the histology that would be observed? Tested Concept QID: 106748 FIGURES: A B C D E Type & Select Correct Answer 1 Figure A 15% (27/176) 2 Figure B 3% (6/176) 3 Figure C 2% (4/176) 4 Figure D 66% (117/176) 5 Figure E 10% (17/176) M 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept
All Videos (1) Login to View Community Videos Login to View Community Videos Carbohydrate Digestion and Absorption Gastrointestinal - Carbohydrate Digestion D 2/14/2015 39 views 5.0 (2)