The Carbohydrates: Sugar, Starch and Fiber Module 1.2

Carbohydrate (Carbs or CHO) Carbohydrate-obtained almost exclusively from plants (fruits, vegetables, grains) Milk is the only animal-derived food with significant carbohydrate. Organic Compound: made of the elements carbon, hydrogen, and oxygen. classified organic due to carbon content compound - has more than one element in its structure. Produced by photosynthesis: converts light energy into chemical energy C6H1206 + 6O2 = 6C02 + 6H2O + energy Chloroplasts composed of proteins with green chlorophyll pigment which absorbs sun’s energy Provides 4 Calories/gram. The preferred fuel for the body; especially brain and nervous system. It is high performance fuel; produces ATP at the fastest rate. Should consume 45-65% of caloric intake from carbohydrate Dietary recommendation for fiber 1.4 gram per 100 caloric intake

Carbohydrate Basics Simple Carbohydrates Sugars Complex Carbohydrate Monosaccharides –single sugar unit Disaccharides – two sugar units Complex Carbohydrate Oligosaccharides and polysaccarides Types Starch Glycogen –storage form of glucose Fiber - indigestible

Categories of Carbohydrate Simple- sugars Monosaccarides Glucose blood sugar Fructose fruit sugar, honey Galactose milk sugars Disaccarides Sucrose - table sugar glucose + fructose Lactose - milk sugar galactose + glucose Maltose - grain sugar glucose + glucose Complex : two forms Polysaccharides: Starch ALPHA linked glucose molecules in starch are broken apart by enzyme alpha-amylase to produce energy. The glucose units that are released are absorbed into the blood stream. Fiber: indigestible BETA linked glucose molecules cannot be broken apart by human enzymes; no energy is produced. The glucose units not released; thus fiber is not absorbed. Cellulose is the most common type of fiber

Monosaccharides Disaccharides α-D-Glucose β-D-Fructose β-D-Galactose α-Sucrose α-Maltose β -Lactose Glucose + fructose Glucose + glucose Glucose + galactose

Complex Carbohydrate Starch is a composite of both types Forms Starch : plant polysaccharide composed of hundreds of repeating units of glucose, digestible by human beings Forms Amylose - Unbranched chains of glucose Constitutes about 20% of starch Amylopectin – branched chains of glucose used as a thickener; enzymes digest more rapidly. Constitutes 80% of starch Starch is a composite of both types http://lh4.ggpht.com/-RP8LFw7ud3s/USHeqHJy4-I/AAAAAAAABLQ/aIacorcZY_A/s1600-h/amylose%252520and%252520amylopectin%25255B7%25255D.jpg

Polysaccharides

Carbohydrate Food Sources Grains, Cereals, & Legumes: Pasta, bread, cold/hot cereal, rice, oats, kidney beans, etc. Fruits & Vegetables Starchy Vegetables: Corn, potato, peas, acorn squash, etc. Plant Carbohydrate Sources Simple carbohydrates: Fruit, table sugar, sweets & sugar sweetened cereals. Complex carbohydrates: Vegetables, starchy vegetables, grains, legumes, & whole grain cereals. Milk (& milk products yogurt & cheese) contain lactose. Honey contains glucose, fructose & small amounts of other sugars. Animal Carbohydrate Food Sources Animal foods usually provide mostly protein & fat. Milk & milk products also provide protein & varying amounts of fat

CHO Enzymatic Action An enzyme is a protein that acts as a catalyst in a biological reaction. Enzyme Amylase digest CHO such as sugars / starch. CHO digestion begins in the mouth stops in the stomach (pH 2.0) where amylase is inactivated or destroyed in when pH falls below 6.5. Digestion completed in the small intestine with the help of the intestinal enzymes (maltase, lactase) Pancreatic amylase joins maltase and lactase to continue the digestion of carbohydrates in the small intestine where pH increases to 6.5. Amylase breaks down starches into a disaccharide. Most starch is broken down to the disaccharide maltose then into single sugars, such as glucose.

Carbohydrate Digestion

Plant Carbohydrate Sources Animal Carbohydrate Food Sources http://www.time-to-run.com/nutrition/wp-content/uploads/carbo.590.jpg Animal Carbohydrate Food Sources http://2.bp.blogspot.com/-ZrZwRr-mRbc/U1fyBDbc0GI/AAAAAAAAGMM/LhYROt-8qWQ/s1600/cow.png

Alcohol: CH3CH2O A clear, colorless volatile liquid (boils @ 172 degrees much lower than water.) Shares similar properties as water therefore travels through the body like water. Easily moves across cell walls into tissues/cells Alcohol is a small molecule that requires no digestive process to be absorbed. Acts as a sedative and central nervous system depressant. Fats and lipophylic substances easily dissolve in alcohol. Used to extract flavors and transport medications A non-nutrient that is not stored in the body. Alcohol forms the glycerol backbone in fatty acids. Supplies energy (7 calories/ 1 gram). One serving per day may reduce heart disease risk but increases cancer risk. http://i247.photobucket.com/albums/gg158/MDA2008/MDA2009/alcoholicbeverages2.jpg

Alcohol Absorption / Metabolism Alcohol is a small molecule that requires no digestive process to be absorbed. About 20% of alcohol is absorbed in the stomach and about 80% is absorbed in the small intestine. Body expels 10% of alcohol through perspiration, lungs, and urine 90% to be metabolized by the liver. A average healthy person’s liver can eliminate .25 oz - 0.5 oz. of alcohol PER HOUR. This leaves the remaining alcohol to continue circulation throughout the body until it is consumed affecting the brain and every tissues, organ and cell. Process: Alcohol + alcohol dehydrogenase → acetaldehyde (carcinogen) acetaldehyde → acetate acetate → carbon dioxide (CO2) and water

Absorption/Metabolism Influences Rate of alcohol metabolism affected by: AMOUNT of alcohol dehydrogenase available FOOD - Fat delays stomach emptying so the alcohol reaches the intestines slower. Alcohol on an empty stomach can reach the absorption within 5 minutes. GENDER Male/female drink ratio = 2:1 female less water; smaller body size; smaller livers Women absorb 30% more alcohol Enzymes – alcohol dehydrogenase is 40% less active in women’s stomachs Blood alcohol concentrations - % of alcohol in the blood. Legal limit = 0.08% (0.08% or one tenth of one percent - 1%) means that there are 0.08 g of alcohol for every dL of blood. BAC 0.35% = unconsciousness threshold BAC 0.40% = coma BAC 0.45% = death