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CARBOHYDRATES. Energy Yielding Nutrient. All CHO have a caloric value of 4 cal /gr Reminder: calorie - measurement of energy Heat energy needed to raise 1 gr of water 1 degree C. Saccaharides. Monosaccharides : C 6 H 12 O 6 The monosaccharides are isomers Fructose Galactose Glucose.
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Energy Yielding Nutrient • All CHO have a caloric value of 4 cal/gr • Reminder: calorie- measurement of energy • Heat energy needed to raise 1 gr of water 1 degree C
Saccaharides • Monosaccharides: C6H12O6 • The monosaccharides are isomers • Fructose • Galactose • Glucose
Isomers • Def: compounds that have the same chemical formula • Champ and Harvey, Biochemistry. Lippincott. 2nd edition
Dissacharides • Created with the Dehyration Synthesis of Monosaccharides • Anabolic Chemical Reaction • C6H12O6 + C6H12O6 = C12H22O11 + H20 • Hydrolysis is a Catabolic Chemical Reaction
Inquiry Exercise • Differentiate between catabolic and anabolic chemical reactions. • Differentiate between dehydration synthesis and hydrolysis
The Dissacharides • Sucrose(cane sugars) = glc + frc • Lactose(dairy sugars) = glc + gal • Maltose(seed sugars) = glc + glc
Inquiry Exercise • List six types of grains • List five types of legumes • List three types of tubers
GLYCOGEN • The structural analogue to starches • It is a glucose polymer found in muscle, the liver, stomach and brain • It is synthesized by the liver when we are in a “fed” state • It is released by liver when blood glucose levels drop….”fast” state
Fiber • Fiber is a non-digestible polysacharide. It does not have caloric value • There are two categories: • Soluble • Insoluble
Soluble Fiber • Easily dissolve in water • They are considered heart healthy because they lower blood cholesterol levels • Pectin is an example of soluble fiber
Insoluble fiber • Do not dissolve in water • Promote colon health by promoting bowel movements, lessening constipation and reducing diverticulosis
Dietary Intake • Recommended dietary fiber intake is 25-35g per day
Chemical Digestion Of CHO • Please refer to the digestive system power point in order to understand carbohydrate pathway.
CHO Enzymes • Salivary Amylase: component of saliva • It functions to begin the digestion of polysaccharides • Neutralized by stomach acid
Pancreatic Amylase • Secreted by the exocrine (acini) cells of the pancreas • It enters the duodenum via the pancreatic and common bile ducts • It breaks down polysaccharides into the disaccharides
Duodenal Enzymes • There are three duodenal enzymes: • Sucrase • Lactase • Maltase
Sucrase • Sucrase breaks down sucrose into glucose and fructose • Is this an anabolic or catabolic chemical reaction?
Lactase • Lactase breaks lactose into glucose and galactose. • Lack of lactase production indicates what digestive disorder? What are the symptoms?
Maltase • Breaks down maltose into to glucose molecules
Absorption • All of the monosaccharides are absorbed and transported to the liver. • All monosaccharides can be converted into glucose by the liver because?
Liver • The liver will • Convert monosaccharides into glucose to be part of blood glucose • Create glycogen: glycogenesis • Create lipids: lipogenesis(remember the carbohydrate hypothesis?)
Function(s) of CHO • Energy • Blood glucose • Glycogen
Function(s) of Fiber • Decrease blood cholesterol • Increase bowel movements
Assigned Readings • Figure 4-10 (carbohydrate digestion) p. 104 • pp. 107-111: Blood Glucose • Table 4-2 (alternative sweeteners) pp. 116-117
Acknowledgements • Unless otherwise noted, all information, images and assignments are adapted or taken from • Whitney and Rolfes (2011). Understanding Nutrition. 12 edition. Wadsworth Cengage Learning.