1 / 16

NS 315 Unit 3: Carbohydrate Digestion and Absorption

NS 315 Unit 3: Carbohydrate Digestion and Absorption. Jeanette Andrade MS,RD,LDN,CDE Kaplan University. Objectives. Definitions Dietary Carbohydrates Digestion/absorption of carbohydrates Glycemic Index Glycemic Load Case Study. Definitions.

kesler
Download Presentation

NS 315 Unit 3: Carbohydrate Digestion and Absorption

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NS 315Unit 3: Carbohydrate Digestion and Absorption Jeanette Andrade MS,RD,LDN,CDE Kaplan University

  2. Objectives Definitions Dietary Carbohydrates Digestion/absorption of carbohydrates Glycemic Index Glycemic Load Case Study

  3. Definitions Carbohydrates:mainly comprised of sugars and starches Sucrase:Splits sucrose into glucose and fructose Lactase:Splits lactose into glucose and galactose Amylase:Enzyme produced in the pancreas and salivary glands that helps in the digestion of starches Glycolysis: anaerobic catabolism of glucose (more about this in Unit 4)

  4. Definitions Dextrins: various polysaccharides obtained from starch by the application of heat or acids and used mainly as adhesives and thickening agents Glycogen:Highly branched polysaccharide of glucose chains stored primarily in liver and muscle to be used as energy Glycogenolysis:The hydrolysis of glycogen to glucose in the liver or muscle to provide energy Glyconeogenesis:The synthesis of glucose from molecules that are not carbohydrates: amino acids and fats. During times when the liver is limited in glycogen stores.

  5. Definitions Glycemic Index: an indicator of the ability of foods that contain carbohydrates to raise blood glucose levels within 2 hours Glycemic load: provide the ranking of the food taking into the account the amount of carbohydrate consumed. GI 100 x grams Carbs consumed

  6. Dietary Carbohydrates:Monosaccharides • Single Sugars- Glucose, Fructose, Galactose • What are some foods that contain these saccharides? • Share same molecular formula: C6H1206

  7. Dietary Carbohydrates:Disaccharides What foods do we see these saccharides in? Sucrose • Two monosaccharides linked together formed a glycosidic bond (loss of 1 H and 1 OH group) • 3 main disaccharides: • Sucrose: glucose + fructose • Lactose: glucose + galactose • Maltose: glucose + glucose

  8. Dietary Carbohydrates:Polysaccharides • Polymers of glucose • Amylose: linear, unbranched chains of several glucose molecules. Forms a colloidal dispersion in hot water (swelling the granules to digest within bodies). • What foods do we see amylose in? • Amylopectin: highly branched chains of several glucose molecules. Insoluble when digested, but specialized enzymes take the big branches in small maltodextrose type chains. • What foods do we see amylopectin in?

  9. Amylose and Amylopectin http://www.chemie.uni-regensburg.de/Organische_Chemie/Didaktik/Keusch/Grafik/amylo-e.gif

  10. Dietary Fiber • Dietary Fiber is generally defined as “plant polysaccharides and lignin which are resistant to hydrolysis by the digestive enzymes of man.” • Cellulose • Pectin • Lignin • Gums • Other (Advanced Nutrition and Human Metabolism 3rded)

  11. Digestion of Carbohydrates • What enzymes aid in breaking down carbohydrates? • What organs aid in breaking down carbohydrates?

  12. Digestion of Carbohydrates After eating starches, amylase is produced from the salivary glands and begins breaking down the compound to maltose, maltotriose and α- dextrins This digestion process then continues throughout the stomach into the small intestine Products of α-amylase are then hydrolyzed into their respective monosaccharides by enzymes located on the brush border of enterocytes. Amylase free in the small intestine is produced by the pancreas. Other enzymes that aid in digestion are maltase, isomaltase, lactase and sucrase.

  13. Absorption, Transport, & Distribution • Absorption of glucose & galactose • Into cell: active transport - SGLT1 • Into blood: diffusion, GLUT2 • Absorption of fructose • Into cell: facilitated transport - GLUT5 • Into blood: GLUT2 • Limited in 60% of adults Cengage-Wadsworth, 2009

  14. Absorption of Carbohydrates http://www.vivo.colostate.edu/hbooks/molecules/hexose_xport.html

  15. Glycemic Index Why may this be important? What problems do you think happen with the glycemic index?

  16. Carbohydrates- Case Study After consuming milk, Bob starts to experience bloating, cramping, and increased gas production. However, when Bob consumes yogurt he does not experience any pain.1. What is wrong with Bob (What is the name of the condition)?2. What causes this condition?3. Why did consuming yogurt not cause the same effects as milk?4. As a nutritionist, what other products or food sources would you recommend to replace milk or alleviate the symptoms?5. What nutrients may be inadequate in the diet if dairy products are not consumed?6. Do you have any problems with consuming milk like Bob? Feel free to share any additional information with the class.

More Related