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 O6OR 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
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
FIBER Dietary fibers are the indigestible portion of plant foods Non-starch polysaccharides such as cellulose Fiber is NOT used for energy
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
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