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34 Cards in this Set
- Front
- Back
Carbohydrates
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4Kcal/gram
largest source of dietary calories low income=more carbs |
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Types of carbohydrates found in plants
types found in animals |
plants: Polysaccharides starch and cellulose(unbranched)
disaccharide sucrose, sugar alcohold sorbitol animals: polysacch glycogen and disacch lactose |
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what is starch made of?
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20% unbranched amylose and 80% branched amylopectin
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what is the AMDR
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acceptable macronutrient distribution range
45-65% of energy intake should be carbs 250g on a 2000 Cal diet |
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RDA
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recommended dietary allowance(meets needs of almost all), 130g/day of carbs based on avg min glc used by brain
actual intakes are 200-300/day |
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EAR
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estimated avg requirement, (meet needs of 50%) 100g/day
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describe carbohydrate digestion in mouth
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mouth: alpha-amylase hydrolyzes random alpha 1,4bonds in starch to get dextrins, maltotriose(alpha 1,4 trisacch of glucose), maltose, and isomaltose(alpha 1,6 disacch of gluc)
beta 1,4 bonds(cellulose) alpha 1,6 bonds(glycogen and amylopectin) are resistant |
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describe digestion of carbs through stomach and pancrease
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stomach - low pH stops alpha amylase
Pancreas -bicarbonate raises pH, pancreatic alpha amylase produces dextrin maltotriose and maltose |
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describe digestion in duodenum and jejunum
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saccharides digested by lactase, sucrase, maltase (digest maltotriose and maltose), and isomaltase(digest dextrins)
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what do the following break down into
lactose sucrose maltose/maltotriose dextrins |
lactose = galac +gluc
sucrose = fruc + gluc maltose = gluc dextrins = gluc |
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Lactose intolerance
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LACTASE DEFICIENCY
primary: loss of lactase at about 2 yrs old (adulat hypolactasia) secondary: diseae or disorder of digestive tract |
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symptoms of lactose intolerance and cause
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lactose is fed on by bact creating gas(H2,CH4, CO2) and lactic acid in large intestine
lactose creates osmotic effect pulling in water to colon |
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lactose intolerance
diagnosis and treatment |
diag - measure H2 in breath after lactose exposure
treatments - reduce dairy products or increase time of exposure makes sure to still eat Ca: tofu,broccoli, kale, collard, yogurt, cheese |
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uptake of monosacchs in gut
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jejunum: enterocytes:
galactose and glucose - Na-Glc transporter SGLT 1, secondary active Fructose: GLUT 5 facilitated diffusion Sugar alcohols: passive diffusion, chewing gum diarrhea |
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uptake of monosacchs from enterocytes to blood
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GLUT2 transports galac gluc and fruc
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insoluble vs soluble fiber
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insoluble: cellulose and lignin
soluble: hemicellulose pectins and gums (oatmeal) metabolized by gut bact |
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what fiber does
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binds H2O
hypoglycemic effect hypocholesterolemic effect fermented by anaerobes |
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H2O binding of fiber
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increases viscosity -> decrease digestion speed, this increases satiety
enlarge and soften stool for shorten fecal transit time(moves faster) |
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hypoglycemic effect
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fiber blunts glycemic response(strength and speed of rise in blood glucose compared to white bread), so less insulin spike
low glycemic index foods can reduce insulin, nonenzymatic protein glycosylation, and of course blood glucose |
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glycemic load
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Glycemic Load = glycemic index (as a %) x carbohydrate content (in grams)
Thus, a food (like carrots) might have a high glycemic index, but the amount of carbohydrate is small, so it can still be a good component of a dietary regimen. GI/100 under 10 is low |
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glycemic index
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ranking of foods based on the glycemic response
under 55 is low |
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fiber and bile acids
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bind bile acids which are derived from cholesterol, and so decrease cholesterol in body
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substances of plant origin haveing a pharm effect
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phytoceuticals
or nutraceuticals |
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fermentation of fiber in colon
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SOLUBLE fiber fermented by anaerobes
produce gas and SCFA(2-4C): fecal bulking(microbial prolif), aid for diarrhea because it promotes uptake of H2O and Na when it's absorbed in colon |
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how much fiber is recommended?
how much is actually consumed DV? |
recomm: 21-28g/day (50 if you have diabetes/hyperlipemia)
actual: 13.5 g/day Daily value - 25g/2000cal diet |
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not enough fiber
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defecation problems,(constipation, hemmroids)
intestinal diverticula from increased pressure needed to expel feces accumulation of fecal matter leading to inflammation and treated with Ab, initial low fiber and then high fiber intake |
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too much fiber
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constipation if not enough water consumed, hunger is quickly satisfied, decreased mineral cations like Ca since they bind to fibers acidic component of fiber
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Simple carbs added to foods
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sweetners
high fructose corn syrup 1960's, now over 20% of carbs, soluble cheap and 40% sweeter than sucrose BUT: bypasses key regulatory steps in glycolysis so more substrate availability for fat syn |
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sugar alcohols
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not abs to same extent. sorbitol has a laxative effect
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saccharin
aspartame sucralose sweetness level? |
saccharin- 300 times sweeter sweet n low
aspartame - 200X sweeter, dipeptide Equal sucralose - 5-600 X,splenda chlorinated sucrose |
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net carbohydrate
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total carbs - fiber and sugar alcohols
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dental caries
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simple carbs broken down to acids by bacterial plaque, acid dissolves tooth enamel
freq and duration of exposure is important fluoride in water, sugar alcohols dont support plaque bacteria |
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high carb low protein meal
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rise in serotonin = sedation and carb craving
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sac-like herniations, a condition which is referred to as diverticulosis. While relatively asymptomatic, this can progress to diverticulitis, a painful condition which may progress to perforation, acute bleeding, obstruction, and/or sepsis. Diverticulosis is thought to result from increased intracolonic pressures, while diverticulitis is an inflammatory condition consequent to sepsis
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Current thinking is that a high-fiber diet, by promoting soft, bulky stools that pass more quickly, protects against diverticular disease, and this has been supported in clinical research.
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