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55 Cards in this Set
- Front
- Back
II. Why we need carbs
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for energy
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III. Simple carbs
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sugars, available carbs
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1. Monosaccharide
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a. Different sweetness
b. Provide E c. Have general CnH2nOn d. ready to go quickly absorbed |
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i. Glucose
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1. monosacc
2. Essential E source 3. One of 2 sugars in disaccharides blood sugar” or dextrose |
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ii. Fructose
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fruit sugar” or levulose
1. monosacc 2. sweetest 3. same form, glucose diff structure 4. honey, cereal, fruits, soft drinks |
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iii. galactose
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1. monosacc
2. part of disaccharide lactose 3. rarely occurs by itself |
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2. Disaccharide
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a. Pairs of monosaccs linked together
b. Condensationes c. Hydrolysis ÷es --- occurs in digestion d. Glucose + monsacc e. Derives from plants except lactose |
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i. Maltose
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malt sugar”
2. has 2 glucose units – alcohol 3. whenever starch breaks ↓ a. carb digestion disacc |
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ii. sucrose
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1. glucose + fructose
2. fruits, veggies, grain 3. sugars (powdered, white, brown) disacc |
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iii. lactose
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1. galactose + glucose
2. main part of milk 3. “milk sugar” diacc |
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Complex Carbohydrates
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1. starches and fibers
2. polysaccharides |
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2. polysaccharides
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a. ed of straight/branches monosaccs
b. Several monosaccs linked together Glycogen, starches, fibers |
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i. Glycogen
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1. many glucoses linked together as highly branched chains fast hydrolysis
2. stored in liver and muscles as a form of glucose 3. not sig food source of carbs 4. not complex carbs in food 5. storage form of glucose ing E for humans 6. found limitedly in meat, some plants polysacc |
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ii. starches
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1. plant polysaccs composed of glucose
2. storage form of glucose E for humans 3. available carb (simple carb) 4. most of glucose supply 5. all starchy foods come from plants, beans, grains, wheat/rice 6. Amylopectin – a component of starch, other is glucose |
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iii. fibers
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1. most are polysaccs
2. no contain monosaccs no E 3. soluble fibers and insoluble fibers |
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3. soluble fibers
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dissolve in water, ex pectin (thicken jelly)
a. viscous – gel like b. fermentable – degree that bacteria can break ↓ fibers to frags c. fruits, oatmeal, barley, legumes d. sponge - absorbs e. decreases cholesterol, 5-10 g/day |
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4. insoluble fibers
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a. nonviscous, less fermented
b. whole grains, veggies c. ↑ bowel movements, increases motility, makes food LEAVE d. don't dissolve in H20 |
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characs of fibers
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5. from plants
6. veggies, fruits, grains, beans 7. each has diff struct |
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structures of fiber
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a. cellulose
b. Hemicelluloses c. Pectins e. Mucilages f. Lignin g. Resistant starches |
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fibers from plants
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a. nonstarch polysaccs --- not digested by humans
b. unavailable carbs b/c can’t break ↓ c. cant be broken ↓ by digestive enzymes like starches |
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a. cellulose
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i. plant cell walls
ii. no broken ↓ humans |
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b. Hemicelluloses
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i. Main pt cereal fibers
ii. Made up monosaccs and branching monosaccs |
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c. Pectins
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i. Backbone of one type of monsacc
ii. Veggies and fruits (citrus) iii. Thicken jelly, keep salad dressing ÷ing |
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d. Gums
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i. Plant secretion
ii. Addititives to thicken foods |
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e. Mucilages
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i. +ed to foods as stabilizers
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f. Lignin
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i. Nonpolysacc
ii. 3-d structure strength iii. Woody taste in veggies |
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g. Resistant starches
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i. Escape digestion/absorption
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How carbs are digested
in mouth |
1. in mouth – saliva, chewing, amylase,
a. amylase – enzyme that hydrolyzes amylose, breaks ↓ carbs i. amylose – form of starch ii. hydrolyzes starch to maltose iii. very little digestion |
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how carbs digested
in stomach |
bolus, stomach acid and protein digesting enzymes -> stop amylase and salivary enzymes
a. ->es satiety b. hydrochloric acid churns food |
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how carbs digested
in small intestine |
most of work of carb digestion, pancreatic amylase (breaks ↓ polysaccs to disaccs), enzymes take apart specific disaccs
a. maltase two glucoses b. sucrase one glucose + one fructose c. lactase one gluclose + one galactose d. now, all polysaccs/disacs are monosaccs |
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how carbs digested
in large intestine |
1-4 hours, all sugs/starches digested,
a. fibers only ones left i. attract H20 soft poo |
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carb absorption
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in SI,
monosaccs enter capillaries of intestinal villi --- monosaccs travel to liver thru portal vein 3. galactose and fructose ed into glucose |
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carb metabolism
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1.store glucose as glycogen
a.liver stores 1/3 of body’s total glycogen b.after meal, blood glucose ↑es i. condensation →ing long branches glycogen c.blood glucose ↓es i.liver cells hydrolysis ii.single molecules, bloodstream d.glucose supplies E to other areas regardless of recent meal e.muscles stores glycogen (other 2/3s) I. use in exercise |
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2. using glucose for E
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a. fuel, breaks in ½
b. can us eother nutrients, fat & ptein but not as easy c. liver only uses for a few hours |
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3. making glucose from Protein
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a. protein has other jobs and fat = no
b. gluconeogenesis – making glucose from noncarb source don’t want this c. protein sparing action –carb/fat ing E, allows ptein used real purpose d. need 50-100 g carbs/day e. 45-65% |
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4. making ketone bodies from fat frags
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a. when lack carbs, ketone bodies form incomplete break ↓ of fat, when excess
i. ketosis 1. ↑ level of ketone, disturbs pH balance |
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5. how many carbs do you need?
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a. 45-65%
b. 225-325 g --- 900-1300 cal c. RDA 130 g d. DV 300 g e. Calculate total |
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Lactose Intolerance
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i. Inability to digest milk sugar lactose
ii. Different than milk allergy |
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VIII. Maintaining Blood Glucose
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homeostasis
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regulators of blood glucose
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insulin
glucagon epinephrine |
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a. insulin
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hormone, released in response to ↑ levels blood glucose
i. purpose: remove glucose from blood into muscle/fat cells allows cells to absorb blood glucose and store as glycogen in liver regulates blood glucose |
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b. glucagon
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i. when blood glucose ↓es (b/t meals), pancreas es glucagon
ii. es ↑ blood glucose, signals liver to release glucose storage |
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a. Epinephrine
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fight or flight” hormone, acts quickly, adrenaline
regulator of blood glucose |
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4. diabetes
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a. disorder of carb metab, inad/ineffect insulin
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i. type 1 diabetes
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1. less common
2. pancreas fails insulin, unknown cause |
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ii. type 2 diabetes
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1. more common
2. cells don’t respond insulin 3. effect of obesity 4. prevent how? Healthy body weight |
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5. hypoglycemia
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a. blood glucose ↓es dramatically es mini attack
b. effect of poorly controlled diabetes c. rare in healthy ppl |
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6. glycemic index
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a. way of classifying foods to potential to ↑ blood glucose
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a. Nutritive sweeteners
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– sweeteners that E, includes sugars/sugar replacers
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b. Hyperactivity
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has been disproven, sugar no link to ADD/ADHD
i. Inattentive/impulsive behavior ↑ freq than age bracket |
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c. Recommendation sugar
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i. No upper limit, no > 25%
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d. Health threat sugar
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i. Dental caries
ii. Might displace other nutrient needs iii. Natural sugars ok: veggies, fruits |
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V. Effects of Fibers
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a. Weight manage, ↓ blood cholest,
b. Prevents i. Colon cancer, diabetes, homerrhoids, appendicitis, diverticulosis |
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c. Excessive amts fiber
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i. Displaces E and nut-dense foods
ii. →es intestinal probs iii. Interfere w/ mineral absorp |
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d. How much fiber we need?
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i. 23-30 g
ii. |