CarbohydrateCarbohydrate

NotesNotes

There are 2 main types of There are 2 main types of carbohydrates.carbohydrates.

Simple carbs Simple carbs – are 1 or 2 sugars are 1 or 2 sugars

in very small in very small molecules. molecules.

Complex carbsComplex carbs– are very large are very large

molecules made of molecules made of many simple carb many simple carb units.units.

Atomic arrangement in a basic Atomic arrangement in a basic sugar molecule.sugar molecule.

6 carbons- 6 carbons- 12 hydrogens- 12 hydrogens- 6 oxygen 6 oxygen atoms atoms

CC66 H H12 12 OO66 OROR CH CH22OO

1: 2: 1 ratio1: 2: 1 ratio

Carbohydrate CharacteristicsCarbohydrate CharacteristicsSubunits are sugars Subunits are sugars

The names of carbohydrates generally end The names of carbohydrates generally end in in ““oseose””Mono (1), Di (2), Poly (more than 2) + Mono (1), Di (2), Poly (more than 2) + saccharide (sugar)saccharide (sugar)

4 kcals/gram of energy4 kcals/gram of energy

Foods that are naturally high in Foods that are naturally high in carbohydrates are more healthful than carbohydrates are more healthful than

those with added sugars because:those with added sugars because: They provide many They provide many

vitamins, minerals vitamins, minerals and protein. and protein.

Added sugars are Added sugars are simple simple carbohydrate, which carbohydrate, which must be used right must be used right away or stored away or stored often as fat.often as fat.

MonosaccharidesMonosaccharidesProvide energy - readily broken down to Provide energy - readily broken down to release energy (metabolism)release energy (metabolism)Serve as building blocks of other Serve as building blocks of other carbohydrates (Disaccharides, carbohydrates (Disaccharides, Polysaccharides)Polysaccharides)

Ex: Glucose (CEx: Glucose (C66HH1212OO66)fructose, galactose )fructose, galactose (with 6 C)(with 6 C)

Food sources for simple sugars are:Fruits CandyDairy products

DisaccharidesDisaccharidesTwo monosaccharidesTwo monosaccharides

The most common disaccharide is The most common disaccharide is sucrose (Table sugar)sucrose (Table sugar)

Other examples:Other examples:– Milk sugar/lactose =glucose + galactoseMilk sugar/lactose =glucose + galactose– Malt sugar/maltose = 2 x glucoseMalt sugar/maltose = 2 x glucose

PolysaccharidePolysaccharideMany saccharides (monomers)Many saccharides (monomers)

Polysaccharide - polymer of sugars Polysaccharide - polymer of sugars

May contain only 1 type of sugar or May contain only 1 type of sugar or more more

To digest polysaccharides, we must To digest polysaccharides, we must first hydrolyze (break down)first hydrolyze (break down)

Ex: Starch (plants) or glycogen Ex: Starch (plants) or glycogen (animals) (animals)

To be continued

Functions of PolysaccharidesFunctions of Polysaccharides

Long term storage of sugars (energy)Long term storage of sugars (energy)

Starch - polymer of glucose in plantsStarch - polymer of glucose in plants

Glycogen - polymer of glucose in Glycogen - polymer of glucose in animals, more branched than starch animals, more branched than starch

STARCHSTARCH

Starch is the most consumed polysaccharide in the human dietFound 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

GLYCOGENGLYCOGENSurplus glucose is linked together and stored as glycogenFunctions as the body’s main energy reserve– If 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 sugar

FIBERDietary fibers are the indigestible portion of plant foods Non-starch polysaccharides such as cellulose

Fiber is NOT used for energy

Insoluble FiberInsoluble 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 FiberSoluble FiberFunctions 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

SugarSugar CarbohydrateCarbohydrate Monosaccharide or Monosaccharide or disaccharidedisaccharide

Additional informationAdditional information

Beet sugar (cane Beet sugar (cane sugar) sugar)

Sucrose Sucrose Disaccharide (fructose and Disaccharide (fructose and glucose) glucose)

Similar to white and powdered sugar, but varied degree of Similar to white and powdered sugar, but varied degree of purification purification

Brown sugar Brown sugar Sucrose Sucrose Disaccharide (fructose and Disaccharide (fructose and glucose) glucose)

Similar to white and powdered sugar, but varied degree of Similar to white and powdered sugar, but varied degree of purification purification

Corn syrup Corn syrup Glucose Glucose Monosaccharide Monosaccharide    

Fruit sugar Fruit sugar Fructose Fructose Monosaccharide Monosaccharide Very sweet Very sweet

High-fructose corn High-fructose corn syrup syrup

Fructose Fructose Monosaccharide Monosaccharide Very sweet and inexpensiveVery sweet and inexpensiveAdded to soft drinks and canned or frozen fruits Added to soft drinks and canned or frozen fruits

Honey Honey Fructose and Fructose and glucose glucose

Monosaccharides Monosaccharides    

Malt sugar Malt sugar Maltose Maltose Disaccharide (glucose and Disaccharide (glucose and glucose) glucose)

Formed by the hydrolysis of starch, but sweeter than starch Formed by the hydrolysis of starch, but sweeter than starch

Maple syrup Maple syrup Sucrose Sucrose Disaccharide (fructose and Disaccharide (fructose and glucose) glucose)

   

Milk sugar Milk sugar Lactose Lactose Disaccharide (glucose and Disaccharide (glucose and galactose) galactose)

Made in mammary glands of most lactating animals Made in mammary glands of most lactating animals

Powdered sugar Powdered sugar Sucrose Sucrose Disaccharide (fructose and Disaccharide (fructose and glucose) glucose)

Similar to white and brown sugar, but varied degree of Similar to white and brown sugar, but varied degree of purification purification

White sugar White sugar Sucrose Sucrose Disaccharide (fructose and Disaccharide (fructose and glucose) glucose)

Similar to brown and powdered sugar, but varied degree of Similar to brown and powdered sugar, but varied degree of purification purification

SOURCE: Mahan and Escott-Stump, 2000; Northwestern University; Sizer and Whitney, 1997; and Wardlaw and Kessel, 2002. SOURCE: Mahan and Escott-Stump, 2000; Northwestern University; Sizer and Whitney, 1997; and Wardlaw and Kessel, 2002.