2 There are 2 main types of carbohydrates. Simple carbsare 1 or 2 sugars in very small molecules.Complex carbsare very large molecules made of many simple carb units.
3 Atomic arrangement in a basic sugar molecule. 6 carbons hydrogens- 6 oxygen atomsC6 H12 O6 OR CH2O1: 2: 1 ratio
4 Carbohydrate Characteristics Subunits are sugarsGlucose is a 6-C sugarThe names of carbohydrates generally end in “ose”Mono (1), Di (2), Poly (more than 2) + saccharide (sugar)4 kcals/gram of energy
5 Foods that are naturally high in carbohydrates are more healthful than those with added sugars because:They provide many vitamins, minerals and protein.Added sugars are simple carbohydrate, which must be used right away or stored often as fat.
6 Insulin is vital to the body’s energy supply It signals the cells to accept glucose, giving them energy to function, triggers liver and muscle cells to remove extra glucose from blood, store it as glycogen for future energy needs.
7 MonosaccharidesProvide energy - readily broken down to release energy (metabolism)Serve as building blocks of other carbohydrates (Disaccharides, Polysaccharides)Ex: Glucose (C6H12O6)fructose, galactose (with 6 C)Food sources for simple sugars are:FruitsCandyDairy products
8 Disaccharides Two monosaccharides The most common disaccharide is sucrose (Table sugar)Maltose = composed of 2 glucoseMilk sugar = lactose (1 glucose + 1 galactose)Malt sugar = maltose (2 x glucose)
9 Polysaccharide Many saccharides (monomers) Polysaccharide - polymer of sugarsMay contain only 1 type of sugar or moreTo digest polysaccharides, we must first hydrolyze (break down)Ex: Starch (plants) or glycogen (animals)
10 Functions of Polysaccharides Long term storage of sugars (energy)Starch - polymer of glucose in plantsGlycogen - polymer of glucose in animals, more branched than starch
11 STARCH Starch is the most consumed polysaccharide in the human diet Found in rice, wheat, corn, and potatoes, peas, bananas, various forms of bread and noodles (including pasta).Cornstarch is used in cooking for thickening foods such as sauces11
12 GLYCOGEN Surplus glucose is linked together and stored as glycogen Functions as the body’s main energy reserveIf there is no glucose, glycogen is available to be broken down into glucose and usedThe conversion of glucose to glycogen (storage – lowers blood sugar by taking it out of the blood stream and storing it as glycogen in the liver) and glycogen to glucose (takes stored glycogen, breaks it down into glucose, and releases it into the blood stream, raising blood glucose) are the usual mechanism for maintenance of normal levels of blood sugar12
13 FIBER Dietary fibers are the indigestible portion of plant foods Non-starch polysaccharides such as celluloseFiber is NOT used for energy13
14 Insoluble Fiber Functions of Insoluble Fiber Move bulk through the intestinesControl and balance the pH (acidity) in the intestinesBenefits of Insoluble FiberPromote regular bowel movements and prevent constipationRemove toxic waste through colon in less timeHelp prevent colon cancerFood Sources of Insoluble FiberVegetables such as green beans and dark green leafy vegetables; Fruit skins and root vegetable skinsWhole-wheat products; Wheat oat; Seeds & Nuts14
15 Soluble Fiber Functions of Soluble Fiber Prolong stomach emptying time so that sugar is released and absorbed more slowly (makes you feel full longer)Benefits of Soluble FiberLower total cholesterol and LDL cholesterol (the Bad cholesterol) therefore reducing the risk of heart diseaseRegulate blood sugar for people with diabetesFood Sources of Soluble FiberOat/Oat branDried beans and peasNuts & BarleyFruits such as oranges and applesVegetables such as carrots15
16 SugarCarbohydrateMonosaccharide or disaccharideAdditional informationBeet sugar (cane sugar)SucroseDisaccharide (fructose and glucose)Similar to white and powdered sugar, but varied degree of purificationBrown sugarCorn syrupGlucoseMonosaccharideFruit sugarFructoseVery sweetHigh-fructose corn syrupVery sweet and inexpensive Added to soft drinks and canned or frozen fruitsHoneyFructose and glucoseMonosaccharidesMalt sugarMaltoseDisaccharide (glucose and glucose)Formed by the hydrolysis of starch, but sweeter than starchMaple syrupMilk sugarLactoseDisaccharide (glucose and galactose)Made in mammary glands of most lactating animalsPowdered sugarSimilar to white and brown sugar, but varied degree of purificationWhite sugarSimilar to brown and powdered sugar, but varied degree of purificationSOURCE: Mahan and Escott-Stump, 2000; Northwestern University; Sizer and Whitney, 1997; and Wardlaw and Kessel, 2002.