MT2 Study sheet - Prof Gregory Aponte PDF

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Prof Gregory Aponte...

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Carbohydrates -

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Macronutrient: 4 kcal/g Made up of Carbon and H2O, hydrogen and oxygen (Glucose C6H12O6) Plant photosynthesis makes carbohydrates (CO2 + H20 (sunlight, plants) C6H12O6 + 02 + H20): need energy for work More you exercise, the more carbohydrates contribute to your total energy (less fat, bc burned) Functions: o (1) Provides energy o (2) Spares protein from making carbohydrates o (3) Provides sweetness o (4) Provides fiber o (5) Enhances some protein function Simple: o Monossaccharides: Glucose, fructose, galactose o Disaccharides:  Maltose (glucose + glucose) molecules join in food in form starch molecules, byproduct of fermentation process  Sucrose (glucose + fructose) found in sugarcane, sugar beets, honey  Lactose (glucose + galactose)  milk sugar Complex (3 + mono): o Oligosaccharides: 3-10 mono, indigestible molecular bonds, colonic bacteria digest- gas, SCFA o Polysaccharides  (1) Starch: amylose + amylopectin, storage form of glucose in plants (grains, legumes, tubers)  (2) Fiber- support structures of leaves, stems and plants, indigestible beta bonds  Health: (1) prevents constipation, hemorrhoids (inflamed veins), divertuculis (inflamed digestive tract, ~bulging pockets form in colon trying to eliminate small, hard stools), colon cancer, (2) promote regular bowel movements and weight loss  (3) Glycogen- storage form of glucose in animals, stored in liver (100g) to maintain BG and muscle (350g) to meet muscle needs  Gluconeogenesis is making glucose from nonglucose (protein- glycogenic AA, triglycerides- glycerol) substrates, glucagon initiates when CHO intake low Carb breakdown: o MOUTH- salivary amylase converts starches into smaller starches, passes through STOMACH, in SI: pancreatic amylase converts small starches to double sugars and brush border enzymes converts double sugars to single sugars, portal vein transfers to liver Starch breakdown in small intestine: o (1) Poly  Oligo  Dis + short glucose chains (2: fibers that cannot be digested by enzymes passes to large intestine and become feces)  (3) enzymes in microvilli digest double sugars into single sugars absorbed in blood Glucose from lumen of SI enter absorptive cell of SI where carrier transports to capillary  travel to liver, in liver, fructose & galactose  glucose o Glucose functions: energy in liver, passed into blood for other cells to use as energy, if consumed in excess energy needs, synthesize FA o Glucose catabolism – glycosis: converts glucose to pyruvate (as metabolized to C-C-CoA, NAD+ converted to NADH, NADH=3ATPs), free energy released form ATP anaerobically, anaerobic cellular respiration

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o (Deamination makes NH2 3-C, 2-C in acetyl CoA, intermediaries in CAC, high energy e-) Pancreatic enzymes (1) lipase, (2) protease (3) Amylase (breaks down carb into absorbable sugars, also found in saliva, shortage causes diarrhea due to undigested starch in colon) Reactions: Hydrolysis (use H20 to breakup) / Condensation (release H20 to create bonds) Insoluble fiber: part of cell well/ not dissolve in H20, contributes bulk to stool (feces)/ cellulose, hemicellulose, good sources- whole grains, fruits, vegetables Soluble fiber: dissolve in H20, viscous (thick, sticky, gel-forming  lower CHO and blood sugar)/ bacteria metabolizes/ gums, pectin/ good sources – fruits, berries, oats, beans o (1) lowers cho – binds w/ bile (2) delay rise in BG –traps nutrients and delay absorption o Enterohepatic circulation of bile bile made from cho in liver, bile stored in gallbladder, SI bile emulsidies fat, bile trapped by viscous fibers in colon lose and feces, other reabsorbed Lactose intolerance: not enough lactase in SI to digest lactose  diarrhea, bloating, intestinal gas Whole gains/ unrefined grains contain bran layers (fiber/vit), germ (v oil and vitE), endorpserm (starch and protein) vs. refined grains BG regulation: o Insulin decreases BG (remove glucose from muscle, liver and fat-storing cells and blood) o Glucagon increases BG (signals glucose production from glycogen and gluconeogenesis in liver and release glucose into blood) Carbs needed to break down fat to CO2 and water, F breaks down to acetyl CoA, then…. o Carbs available: combines C-C-CoA with oxaloacetate for CAC o Carbs unavailable: acetyl CoA form ketone bodies for energy, accumulation in blood, urine o Acetyl CoA from (1) Pyruvate (2) Alcohol (3) Ketogenic AA Carbs can converted to FA if excess calories are consumed, lipogenesis- making fat from nonfat substances, occurs in liver Sweet taste indicate energy rich foods Type 1 (juvenile onset) diabetes – 5-10%: autoimmune disease affecting beta cells of pancreas, need insulin injections, symptoms: frequent urination, unusual thirst, extreme hunger, unusual weight loss, extreme fatigue, irritability, ketone bodies Type 2 (adult-onset) diabetes) – 95%, resistance or reduced response to insulin, diet, exercise and oral meds help o Risk factors: over 45, family history, non-Caucasian, overweight, sedentary lifestyle, low HDL or high TG Hypoglycemia: low BG, causes shakiness, swelling, anxiety / reactive hypoglycemia: pancreas secretes too much insulin after high carb meal Glycemic Response: food’s potential to raise BG levels, higher the glycemic index (GI) higher BG o Influenced by amount and type of CHO and protein, fat and fiber content

Dietary Fat and Lipids Functions of Lipids (1) provide energy (2) energy storage (TG in adipose tissue) (3) protection/ insulation (4) cell membrane component (5) compound synthesis (6) absorb and transport fatsoluble vitamins (7) satiety, flavor, taste and aroma of foods - Types of Lipids (1) Triglycerides (TG) (2) Free FA (3) Phospholipids (4) Sterols TRIGLYCERIDES: 3 FA molecules (long carbon chains bound to hydrogen) + 1 glycerol (3-C alcohol backbone) - Condensation reaction: TG synthesis // Hydrolysis reaction: lipase - FA chain length : short LDLs) Feasting: excess energy consumed- stored as TG in adipose tissue Fasting: no food eaten for a while, TG from adipose tissue broken down, releasing FA as energy Lipolysis: catabolism of TG, TG  (broken down by lipase)  glycerol (converted in liver to pyruvate which can make acetyl CoA and glucose) + fatty acids (released into bloodstream) Carbs needed to break down fatty acids (oxaloacetate  CAC), unavailable – make ketone bodies o Ketones are used for energy: (1) converted back to acetyl CoA and enter CAC, slow because lack oxaloacetate (2) brain can run on energy from ketones (3) ketones spare protein from being broken down o Ketones lost in urine and breath Cardiocascular disease (CVD): abnormal condition of heart and blood vessels o Atheroscletosis: narrowing and hardening of blood vessels that supply blood to the heart muscle, brain and other parts of body o Coronary Heart Disease (CHD): heart not receiving enough blood o Stoke: brain not receiving enough blood

MINERALS - Cofactors, esp trace minerals: (1) Combine with incomplete enzyme to form active enzyme (2) active enzyme binds with molecules to make products (3) products released, min e separated - 3 principles: bioavailability/ competition/ chemical form - Compounds that interfere with min absorption: OXALATES (Ca, Fe), TANNIN (Fe), PHYTATES (Ca, Fe, Zn, Mg) - CALCIUM functions: o (1) Bone structure – trabecular bone (spongy)/ cortical bone (compact) o (2) Release neurotransmitter  decrease Ca caused muscle cramps o (3) Muscle contraction o (4) Regulate enzyme activity o (5) Blood clotting - Bone remodeling continuous: adjust to new strength, shape, and replace degrading matrix/ ~key players: osteoblasts, osteocytes, osteoclasts - Osteomalacia (normal matrizx decreased Ca) vs. Ostroporosis (normal matrix to Ca, both reduced, thinning bones, risk factors- female, race, small stature, sedentary, menopausal women) - Calcitriol: hormone produced by Vit D3, only hormone that induces intestine to absorb dietary Ca++, w/o vit D and conversion into calcitriol, dietary Ca++ absorption is severely impaired - PHOSPHORUS: ATP, phosphate compound, phospholipid, lipoprotein (everywhere) o Functions: teeth structure/ bone mineralization/ energy/ protein modification/ phospholipids/ acid-base/ signal molecule/ component of RNA & DNA/ activates enzymes - Trace minerals: iron/ copper/ zinc- essential, less than 100 micrograms/day, nor energy source functions: (1) enzyme components and (2) DNA synthesis - Free Radicals damage: molecule with an odd# non-paired electrons, unstable atom w/ unpaired ein outer shell o e- can be involved in many reactions o Causes: oxidation reactions, immune system, pollution, radiation - IRON

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o D: reduced O2 carrying capacity and decreased energy production, fatigue/ impaired work performance/ cognitive abnormalities in children/ body temp red/ decreased immune function/ severe- anemia  iron-deficiency anemia o E: free radical damage, susceptibility to infection, risk of heart disease, hemochromastosis (genetic, damage in tissue, accumulation of Fe in hemosiderin in liver and other tissues) o Functions: 02 transport (hemoglobin and myoglobin), cofactor, immune function o Source: animal products (heme and nonheme), plant (only nonheme iron)  Non Heme Iron Absorption: enhanced by vitC, gastric acid, meat protein factor ; inhibitor- Ca, oxylate, polyphenols, antacids  Heme iron absorption: broken down Fe2+  Fe3+  Transferrin Fe3+  Transferrin receptor takes into the cell  Ferritin (storage) o Fe absorption influenced by (1) blood iron stores (2) RBC synthesis in bone marrow (3) blood hemoglobin conc (4) blood oxygen content (5) presence of inflammatory cytokines o Pools of iron: (1) storage- ferritin / (2) transport- transferrin/ (3) cellular- enzymes, transport proteins o Toxicity: constipation, nausea, vomit, reduced Zn uptake, Fe overload o Iron-containing proteins  Hemoglobin: carries O2 and CO2 in blood  Myoglobin: carries O2 to muscles  Cytochromes: energy generation  Ferritin storage for iron, excess becomes hemosiderin  Transferrin: transports iron in blood COPPER o 30-40% from diet is absorbed, high Zn intake inhibits Cu absorption also reduced by high intake of iron/metals/ vit Z and antacids o Absorbed copper is bound to albumin and transported to liver o Takes in O2, takes in nickel and zinc o Binds to ceruloplasmim (protein) which allows copper to transport ZINC o Source: meat, fish, oysters are rich ones, also dairy, whole grains and legumes (almost everywhere) o Functions: (1) Cofactor/ (2) Stabilizes protein that regulates gene expression: zinc fingers/ (3) Functions in 300 enzymes o In the digestive tract: absorption regulated by zinc transport proteins, amount of zinc that enter blood regulated by metallothionein (stores zinc) o Deficiency: needs protein synthesis for growth o Toxicity: nausea, vomit, immune suppression, impaired Cu intake

Water-soluble vitamins -

Vit B (8 variations- TRNBPVFV) & C // Fat-soluble: ADEK Required in diet (N can be synthesized), help protein/carb/fat metabolism “Natural vitmins” less bioavailable than “synthetic vitamins” DRI Dietary Reference Intakes- EAR/RDA/AI/UL Water soluble vs. fat soluble vit o W: dissolve in water, no real stores, readily excreted, F: coenzymes (activates enzyme) /antioxidants, absorbed by portal system, not required daily, high doses can be toxic, losses through cooking/food storage/ milling o F: stored in tissues, remain in adipose and liver, F: hormones/blood clot/ antioxidants, absorbed by lympatic system with fats (chylomicrons), not required daily, high doses toxic

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Deficiencies: Beriberi (T), Ariboflavinosis (R), Pellegra (N), Convulsions/ anemia (V6), Megaloblastic anemia (Folate), Pernicious anemia (V12), Scurvy (C) Vit B functions (1) coenzyme (2) hematopoietic (blood cell synthesis) (3) energy release [carb/AA] THIAMIN o Beriberi: damage to nervous system, heart, muscle weakness, adema, common in alcoholics o Coenzyme T pyrophosphate needed for (1) carb/AA metabolism & (2) RNA/DNA production [redox] RIBOFLAVIN o Ariboflavinosis: sore throat, swollen mucous membranes, dermatitis, stunted growth o Component of 2 coe FMN, FAD involved in redox reactions in metabolism [AA] NIACIN: 2 forms- nicotinic acid, nicotinamide o Coe NAD/NADP assists with energy metabolism o Can be made from AA tryptophan (corn protein has low levels, coffee has high levels) o Pellagra: usu. in ppl consuming low-protein, corn-based diets, diarrhea, dermatitis, dementia, death o High doses of niacin treats hypercholesteremia [FA, glucose] BIOTIN o Coe involved in energy metabolism, esp important for gluconeogenesis and FA synthesis o Content determined for few foods, high in egg yolk o Deficiency only seen with large consumption of raw egg whites over time, high thinning, hair color loss, red rash [fat] PANTOTHENIC ACID o Coe A for fat metabolism, no toxicity, rare deficiency [AA, heme, glycogen] VITAMIN B6/ PYRIDOXINE o Group of 3 related compounds o Coe for over 100 enzyme in AA metabolism - for glycogen breakdown and first enzyme in heme biosynthesis o Required for transamination (remove nitrogen from AA) o Deficiency: dermatitis, anemia, convulsions, toxic in high doses – nerve damage VITAMIN C (ASCORBIC ACID) o Required by primates and guinea pigs o Deficiency: scurvy, appetite loss, retarded wound healing, bleeding gums and capillaries o Functions: (1) formation of collagen (bone/skin/gums), (2) antioxidants, (3) immune function, ($) hormone/neurotransmitter synthesis o Megadoses cause intestinal discomfort Micronutrients involved in blood formation- ANEMIA: low blood hemoglobin o Anemia in folate/ vitamin B12 FOLIC ACID (unnatural form of folate) o Converted to reduced folate derivatives and metabolized to coe forms o Folic acid is more stable than naturally-occuring folates, twice more bioavailable o Folate coe functions: (1) synthesis of RNA/DNA (2) AA metabolism o Deficiency: megaloblastic anemia, few but enlarged RBC, symptoms of anemia  Deficiency affects all fast growing cells including intestinal mucosa leading to malabsorption of other nutrients  Common in pregnancy (Fortification early on), prevent neural tube defect/spina bifida (birth defect in babies)  May impaire cognitive function in elderly o Poor folate status (1) associated with increased cancer risk, anti-folate drugs used to cure cancer, concerns raised that folate fortification accelerates growth rate of preexisting tumors VITAMIN B12

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o Deficiency: pernicious anemia and demyelination of spinal cord o Functions: (1) Coe for AA catabolism, (2) maintains myelin sheath of nerve fibers (3) metabolism of AA homocysteine o VB12 transport: needs binding proteins, intrinsic factors produced by parietal cells in stomach needed for absorption, transcobalamin II required for B12 transport – transport deficiency!! o Pernicious anemia: (1) causes defective DNA synthesis (2) destroys parietal cells o Available from animal sources, vegans obtain from fortified foods/ supplements Folate and V12 required for AA homocysteine metabolism, low intake increases level of plasma homocysteine associated with greater cardiovascular and cerebrovascular disease risk

Discussion 4: supplements -

Products taken by mouth that contains dietary ingredients that supplement the diet

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Dietary ingredients: vitamins, minerals, herbs, AA, extract Considered food, not drugs (not stricylu regulated in safety and effectiveness), advertising by FTC CGMP (FDA) Current Good Manufacturing Practices: product must contain right ingredients and correct dosage USP US Pharmacopeia: voluntary, test contents, processing, purity Supplement label (mandatory): ingredients/ amount per pill/ %DV/ name of plant if plant-based/ daily dosage Also added: health/nutrient claims, structure claims, lack of nutrient caused disease, statement of general well being CANNOT say treat/cure/prevent disease (usually due to particular nutrient deficiency)

Discussion 5: fat -

Hydrophobic, soluble in organic solvent (C+H) Lipids: (1) energy (2) cell membrane (3) ADEK (4) Nerves Saturated fats vs. Unsaturated fats Trans fat: unhealthy (more LDL, less HDL), add hydrogen atoms to hydrogenate veg/polyunsat oil to straighten chain and remove cis double bonds, longer shelf life, artificial 1980 DGA declared sat fat and cho not good VS. 2014 both ok depending on type and how much you use, good for skin Americans eat 1:16 ratio of omega-3 to 6, need balance

Discussion 6: food security -

Food security: (1) availability and (2) access to nutritious diet for healthy life Levels: high, moderate/ marginal, low, very low Availability: food deserts Access: lack of money, costs too much Also important utilization (education) + stability (natural/ economic disasters – shock, seasonal/monthy food insecurity due to food stamps or paychecks – cyclical) Health: energy dense foods are cheap and lead to diseases, advertising, healthcare, minorities 3 programs: o SNAP (biggest program): food stamp, allow wide range of foods (not non-foods) o WIC (women infants and children at nutritional risk): for pregnant, breastfeeding and postpartum o NSLP: students in public school o ** federal poverty line: if below a certain point, qualify for these programs...