Carbohydrate Notes

There are 2 main types of carbohydrates. Simple carbs are 1 or 2 sugars in very small molecules. Complex carbs are very large molecules made of many simple carb units.

Atomic arrangement in a basic sugar molecule. 6 carbons- 12 hydrogens- 6 oxygen atoms C6 H12 O6 OR CH2O 1: 2: 1 ratio

Carbohydrate Characteristics Subunits are sugars Glucose is a 6-C sugar The names of carbohydrates generally end in “ose” Mono (1), Di (2), Poly (more than 2) + saccharide (sugar) 4 kcals/gram of energy

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.

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.

Monosaccharides Provide 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: Fruits Candy Dairy products

Disaccharides Two monosaccharides The most common disaccharide is sucrose (Table sugar) Maltose = composed of 2 glucose Milk sugar = lactose (1 glucose + 1 galactose) Malt sugar = maltose (2 x glucose)

Polysaccharide Many saccharides (monomers) Polysaccharide - polymer of sugars May contain only 1 type of sugar or more To digest polysaccharides, we must first hydrolyze (break down) Ex: Starch (plants) or glycogen (animals)

Functions of Polysaccharides Long term storage of sugars (energy) Starch - polymer of glucose in plants Glycogen - polymer of glucose in animals, more branched than starch

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 sauces 11

GLYCOGEN Surplus glucose is linked together and stored as glycogen Functions as the body’s main energy reserve If there is no glucose, glycogen is available to be broken down into glucose and used The 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 sugar 12

FIBER Dietary fibers are the indigestible portion of plant foods Non-starch polysaccharides such as cellulose Fiber is NOT used for energy 13

Insoluble Fiber Functions of Insoluble Fiber Move bulk through the intestines Control and balance the pH (acidity) in the intestines Benefits of Insoluble Fiber Promote regular bowel movements and prevent constipation Remove toxic waste through colon in less time Help prevent colon cancer Food Sources of Insoluble Fiber Vegetables such as green beans and dark green leafy vegetables; Fruit skins and root vegetable skins Whole-wheat products; Wheat oat; Seeds & Nuts 14

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 Fiber Lower total cholesterol and LDL cholesterol (the Bad cholesterol) therefore reducing the risk of heart disease Regulate blood sugar for people with diabetes Food Sources of Soluble Fiber Oat/Oat bran Dried beans and peas Nuts & Barley Fruits such as oranges and apples Vegetables such as carrots 15

Sugar Carbohydrate Monosaccharide or disaccharide Additional information Beet sugar (cane sugar) Sucrose Disaccharide (fructose and glucose) Similar to white and powdered sugar, but varied degree of purification Brown sugar Corn syrup Glucose Monosaccharide   Fruit sugar Fructose Very sweet High-fructose corn syrup Very sweet and inexpensive Added to soft drinks and canned or frozen fruits Honey Fructose and glucose Monosaccharides Malt sugar Maltose Disaccharide (glucose and glucose) Formed by the hydrolysis of starch, but sweeter than starch Maple syrup Milk sugar Lactose Disaccharide (glucose and galactose) Made in mammary glands of most lactating animals Powdered sugar Similar to white and brown sugar, but varied degree of purification White sugar Similar to brown and powdered sugar, but varied degree of purification SOURCE: Mahan and Escott-Stump, 2000; Northwestern University; Sizer and Whitney, 1997; and Wardlaw and Kessel, 2002.