1. C HAPTER 2 Carbohydrates 1

2. N ATURE OF C ARBOHYDRATES Relation to energy Energy is necessary to sustain life Basic fuel source*- the body can rapidly breakdown these stores of quick and sustaining energy foods such as sugars and starches Energy production system- 1. changes basic fuel, 2. carries refined fuel to places it is needed and 3. burns the refined fuel #1 energy source for the body Pg 13&14 pg 13&14 pg13 2 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

3. C LASSES OF C ARBOHYDRATES Monosaccharides- requires no further digestion Simple sugar* Simple carbohydrate Glucose PRIMARY SOURCE OF FUEL * Fructose FOUND IN FRUITS OR HONEY Galactose COMES FROM DIGESTION OF MILK pg15 3 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

4. M ONOSACCHARIDE FOODS 4 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

5. C LASSES OF C ARBOHYDRATES, CONT ’ D Disaccharides Double sugar Simple carbohydrate Sucrose COMMON TABLE SUGAR* Lactose SUGAR IN MILK Maltose DIGESTIVE BREAKDOWN OF STARCH- Glucose + Fructose= Sucrose* Glucose + Galactose= Lactose* Glucose + Glucose= Maltose* pg16 5 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

6. DISACCHARIDES 6 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

7. C LASSES OF C ARBOHYDRATES, CONT ’ D Polysaccharides Starch – Most important polysaccharide* Glycogen – Found in animal muscle tissue (liver) Dietary fiber – Does not have energy value pg16 7 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

8. POLYSACCHARIDES 8 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

9. S TARCH Most significant polysaccharide in the diet* Whole grains retain the bran layer, inner germ, and endosperm, including the nutrients naturally found in the plant Enriched grains are refined grains that have nutrients added back to them* pg16 9 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

10. F OCUS ON D IETARY F IBER Not digestible* Important in health promotion and disease prevention Three types important in human nutrition: Cellulose – provides bulk in the diet* Noncellulose polysaccharides – absorbs H2O, swell to a larger bulk* Lignin – non CHO3 type of dietary fiber. Combines with bile acids and cholesterol* preventing their absorption OATMEAL, RAISIN BRAN, BLACK BEANS ARE A GOOD SOURCE OF FIBER pg16 10 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

11. F OCUS ON D IETARY F IBER, CONT ’ D Cellulose- chief part of the framework of plants Remains undigested in the gastrointestinal tract and provides bulk to a diet* Bulk helps move the food mass through the intestine Examples: Stems, leaves of vegetables Coverings of seeds and grains pg17 11 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

12. G OOD SOURCES OF FIBER 12 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

13. F OCUS ON D IETARY F IBER, CONT ’ D Noncellulose polysaccharides* Absorb water and swell to a larger bulk- prevents spastic colon Provides fermentation material on which colon bacteria can work Examples: pectins, gums, mucilages, algal substances Lignin Only noncarbohydrate type of dietary fiber Combines with bile acids and cholesterol in the intestine, preventing their absorption Woody parts of plants- strawberries and flaxseeds pg18 13 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

14. F OCUS ON D IETARY F IBER, CONT ’ D Divided into two groups based on solubility Insoluble- used for relief of constipation Soluble- ability to bind to bile acids and lowers the cholesterol level Many health organizations recommend increasing intake of dietary fiber 38 g/day for men 25 g/day for women pg17 14 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

15. I NSOLUBLE FIBER 15 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

16. F OCUS ON D IETARY F IBER, CONT ’ D Sudden increases can result in gas, bloating, constipation Excessive amounts of dietary fiber can trap small amounts of minerals and prevent absorption into the gastrointestinal tract pg21 16 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

17. S UMMARY OF D IETARY F IBER C LASSES 17 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

18. E NERGY F UNCTION OF C ARBOHYDRATES Basic fuel supply Energy for physical activities and all work of body cells* # 1 source for energy Voluntary and Involuntary energy Voluntary- eating, walking, running, talking Involuntary- respirations, cardiovascular Reserve fuel supply Provided by glycogen- reserves in liver and muscles Maintains normal blood glucose level Pg 22 pg 22 18 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

19. S PECIAL T ISSUE F UNCTIONS OF C ARBOHYDRATES Liver Glycogen reserves protect cells from depressed metabolic function Found in liver and muscles (reserves) Protein and fat Carbohydrates regulate proteins and fat Protein-sparing action - results in sufficient amounts of carbohydrates in the diet pg22 19 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

20. F UNCTIONS OF LIVER 20 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

21. S PECIAL T ISSUE F UNCTIONS OF C ARBOHYDRATES, CONT ’ D Heart Glycogen is vital emergency fuel for heart muscle Fatty acids is the preferred fuel for the heart* Central nervous system Brain dependent on minute-to-minute supply of glucose Sustained and profound shock from low blood sugar may cause brain damage and can result in coma and/or death pg22 21 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

22. H EART ANATOMY 22 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

23. C ENTRAL NERVOUS SYSTEM 23 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

24. D IGESTIBLE F OOD S OURCES OF C ARBOHYDRATES Starches Provide fundamental complex carbohydrates Central type of food for a balanced diet Provide important sources of fiber and other nutrients Sugars High-sugar diets carry health risks Sugar is not the villain. It is the quantity that is consumed per individual. Average American consumes 10 Tbsp per day pg24 24 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

25. D IGESTION OF C ARBOHYDRATES Mouth Mechanical or muscle functions break food mass into smaller particles Chemical process- salivary amylase-secreted by the parotid gland. Salivary amylase acts to breakdown starch Mastication is the process of chewing food and mixes with saliva Stomach Peristalsis continues mechanical digestive process-wave like contractions Food mass is thick and creamy- chyme Ph in stomach is acidic pg24 25 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

26. D IGESTION OF C ARBOHYDRATES, CONT ’ D Small intestine- Main place for digestion of starch* Alkaline environment Peristalsis continues mechanical digestion Pancreatic secretions- pancreatic amylase-(breakdown of starch) enters duodenum through the common bile duct Intestinal secretions- sucrase, lactase and maltase- acts on disaccharides to break them down Lactose intolerance, the inability to break lactose down into monosaccharide units Symptoms include-bloating, gas, diarrhea Pg 25-26 pg26 26 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

27. S MALL INTESTINE 27 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

28. B ODY N EEDS FOR C ARBOHYDRATES Dietary Reference Intakes 45% to 65% of adult’s total caloric intake should come from carbohydrate foods Limit sugar to no more than 25% of calories consumed Dietary Guidelines for Americans, 2005 Does not provide a specific caloric number or percentage, but does provide recommendations 28 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

29. S UMMARY Carbohydrates are the primary source of energy for most of the world’s population. Carbohydrates are distributed as plant sources as grains, legumes, vegetables, and fruits. The two basic types of carbohydrates are simple and complex. Simple carbohydrates are composed of single- and double-sugar units (monosaccharides and disaccharides) 29 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.

30. S UMMARY, CONT ’ D Complex carbohydrates are composed of many sugar units. Dietary fiber is a complex carbohydrate that is not digestible. Dietary fiber is found mainly in the structural parts of plants. Carbohydrate digestion begins in the mouth, continues in the stomach, moves to the small intestine, and finally arrives in the large intestine and exits through the anus. 30 Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.