Nutr CH 4

-Body's Preferred Source of energy for brain/nerves and developing red blood cells (glucose) -Principle source of nutrition, world-wide

45-65% of Calories

carbon, hydrogen, oxygen

glucose, fructose, galactose

-maltose (glucose+glucose) -sucrose (glucose+fructose) -lactose (glucose+galactose)

-Is part of every disaccharide -Makes up most polysaccharides -Serves as an essential energy source for all body's activities -Commonly known as blood sugar

-chief food source of energy for all the worlds people -Long, branched or unbranched chains of hundreds or thousands of glucose molecules -Found in grains like wheat or rice, tubers and legume -Plants store glucose as starch -When you eat a plant your body hydrolyzes (breaks down) the starch to glucose to be used for energy

-important storage form of energy in the body -Stored in liver and muscles -A hormonal message (from glucagon) "release energy" arrives at the storage site in a liver or muscle cell, enzymes respond by attacking all the many branches of each glycogen simultaneously, making a surge of glucose available

-Sweetest sugar -Exactly the same chemical formula as glucose but its structure differs -Occurs in fruit & honey -Other sources include products soft as soft drinks, ready to eat cereals and desserts that have been sweetened with high fructose corn syrup

-Forms the sugar in milk -Rarely occurs naturally as a single sugar -Has the same numbers and atoms as glucose and fructose in yet another arrangement

Glucose (monosaccharide) is the primary source of energy for brain and nerve cells and developing red blood cells.

Fruits, Milk, Starches (ex. bread, rice, pasta), Starchy vegetables (ex. potato, squash, peas, corn) and added sugars (ex. sugar, honey, agave, molasses)

-glucose + glucose -Produced whenever starch breaks down

-glucose + fructose -Tastes sweet -Table sugar refined from sugar beet and sugarcane

-glucose + galactose -Principle carbohydrate of milk (milk sugar) -Contributes 30 to 50% of calories in milk depending on fat content

Reaction linking 2 molecules together (hydroxyl and hydrogen)

Reaction breaking 2 molecules apart (finished product is H and OH)

-A condition that results from inability to digest the milk sugar lactose -Characterized by bloating, gas, abdominal discomfort and diarrhea -Differs from a milk allergy (allergic response caused by an immune reaction to the protein in milk)

-activity is highest immediately after birth -activity usually declines during childhood and adolescence to 5 to 10 percent of the activity at birth -Only a small percentage (about 30%) will retain enough lactase to digest and absorb lactose efficiently throughout life

-Composed of many monosaccharides linked together -dietary sources: starch and fiber -bodys stored form: glycogen

-All starchy foods come from plants -Grains are the richest source of starch which provides much of the energy for people all over the world

-Provide structure in stems, trunks, roots leaves and skins of plants -Bonds cannot be broken down by enzymes in the body -Since they go undigested, they contribute no monosaccharides and therefore little or no energy -Bacteria in colon break down some types -Classified as non-starch polysaccharides

-associated with protecting against heart disease -Dissolve in water; Form gels (viscous) -Digested by bacteria in the colon (fermentable) -Found in oats, barley, legumes, citrus fruits

-associated with alleviating constipation and bowel health -Do not dissolve in water; Do not form gels (non viscous) -Less readily fermentable -Found in whole grains (bran) and vegetables

-Fibers extracted from plants or; -Manufactured and then added to foods or used in supplements -Have beneficial health effects

includes both dietary fibers and functional fibers

Large starches (polysaccharides) > Disaccharides > Monosaccharides

Salivary Amylase

-To a small extent stomach's acid breaks down starch but it contains no enzymes that work on carbohydrates -Fibers linger in the stomach and delay gastric emptying providing a feeling of fullness

-Most carbohydrate digestion occurs here with the assistance of pancreatic amylase -Specific disaccharide enzymes from intestinal cells break them down to monosaccharides

Fibers attract water

-Fibers attract water which softens the stools for passage -Bacteria in colon will ferment some fibers -Fibers can contribute some energy (1.5-2.5 kcals/gram)

-Monosaccharides absorbed in the small intestine -Absorbed into the blood and shipped to the liver

Glucose is key player

-(1/3rd of glycogen) -Condensation into glycogen -Hydrolysis for release of glucose when needed

-(2/3rds of glycogen) -Hoards glycogen for use during exercise

-Making glucose from protein

-Fuels most of body's cells -Preferred source for brain, nerve cells, and developing red blood cells -Cellular breakdown of glucose

-Made from fat fragments -Using glucose to make fat -Inadequate supply of carbohydrates -Fat metabolism shifts -alternative food source during starvation -Ketosis disturbs normal acid-base balance

Moves glucose from blood into cells

Brings glucose out from storage

-Food you eat (via the small intestine) -Glycogen (from liver or muscle) -Gluconeogenesis (creation of glucose from protein)

-If blood glucose levels are too low -a person may become dizzy and weak

-If blood glucose levels are too high -A person may become fatigued

-("Fight or Flight" hormone) -Signals the liver to release glucose -When a person experiences stress, this hormone makes sure all cells have energy in emergencies -Notice all the cells that need fuel during stress

-How quickly glucose is absorbed after a person eats -How high blood glucose rises, and how quickly it returns to normal -Ideal Response = Slow absorption, modest rise in blood glucose and a smooth return to normal

A method of classifying foods according to their potential for raising blood glucose

-On average, people in U.S. consume about 30 teaspoons of sugar/day -1 teaspoon = 5 grams = 20 calories

contain a few vitamins and mineral but not many

Non-nutritive sweeteners Large doses and adverse effects

-herbal product -Generally recognized as safe (GRAS)

-Provide kcalories -Benefits and side effects

-the level of consumption that if maintained everyday throughout a person's life would still be considered safe by a wide margin.