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85 Cards in this Set
- Front
- Back
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Conditoinally Acquired essential |
-when something is functionally wrong and makes an amino acid essential 1. phenylketronuria: phyalanine hydroxylase cannot convert Phe to Tyr which can cause disorders and disability (limit phe intake and add tyr) 2. Chorrosis/liver disease: Tyr and Cys usually made from Phe and Met need to be supplemented |
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Basic Amino Acids |
-lysine: essential, simple, lacking in plants -arginine: non-essential bc can be made in urea cycle -hisditine: essential, used to make histamine so important to children |
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Acidic amino acids |
-aspartate: non-essential, transminated to oxaloacetate in protein catabolism, delivers N to urea cycle -glutamate: non-essential, transaminated to alpha-ketoglutarate for krebs, NH3 source, makes GABA, carries N to liver and kidney |
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Neutral Amino Acids |
-glycine: to make porphrin ring in hemoglobin -alanine: carries N between tissues -Leucine, Isoleucine, Valine: BCAA, essential |
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Hydroxylated Amino Acids |
-serine:essential -threonine: non-essential |
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Sulfur Containing Amino Acids |
-cysteine: non-essential, made from Met, dissulfide bonds and glutathione synthesis -Methionine: essential and low in legumes |
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aromatic amino acids |
-phenylalanine: essential -tyrosine: non-essential, spares Phe, makes neurotransmitter -tryptophan: essential, makes serotonin and niacin -proline: non-essential, makes collagen for extracellular matrix |
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Phosphorylation |
PTM to serine, threonine and Tyrosine -phosphorus dependant |
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hydroxylation |
-lysine: copper dependant to make elastin subunit -proline: vitamin C dependant to make collagen subunits |
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gamma carboxylation |
-vitamin K dependant to make carboxylated glutamate that can bind Ca2+ for blood clotting -basically makes proteins into Ca2+ chelators |
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iodination |
-forming thyroid hormones -regulating metabolic rate |
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ADP ribosylation |
-niacin (B3) used to make NAD+ which can be broken into ADP-ribose and nicotinamide -ADP-ribose goes to acceptor protein -DNA repair and regulation of protein function |
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Protein Digestion in Stomach |
-parietial cells secrete HCl in response to gastrin, Ach and histamine -this denatures proteins and activates pepsin from pepsinogen -pepsin cleaves polypeptide chain (endopepsidase breaks peptide bonds) |
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Protein Digestion at the Pancreas |
-pancreatic juice contains zymogens -an endopepsidase cleaves trypsinogen to trypsin which will then make chymotrypsin, elastase, and carboxypeptidase A/B -juice also contains aminopeptidase |
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protein digestion at the small intestine |
-proximal absorbs most AA by facilitated diffusion or active transport through sodium dependant transporter -PEPT1 for active transport that is used when concentration gradient runs out, after ~40% absorbed -30-40% of AA used in enterocyte itself |
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Protein Digestion at Liver |
-Absorbed AA go through portal vein to liver -clears about 50-65% of AA and uses 20% of these for synthesis and 80% of them for metabolization -creates free amino acids -BCAA go straight to systemic circulation |
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Four Components of Protein Quality |
1. composition 2. toxicity 3. digestability 4. species consuming it |
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assessing protein quality |
Protein efficacy ratio(PER)=gain in body mass/protein intake chemical score (CS)=[abundance of first limiting AA/abundance of that AA in egg] x 100 nitrogen balance=N intake-N loss; should be around 0, lower is bad |
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Low protein |
Marasmus: generally low causes starvation mode Kwashiorkor: enough cals but no protein -both have immune disfunction -spectrum between the two |
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Differences in Fate of NH3 |
1. in fed forms glutamine and alanine and goes to liver 2. fed state involves both liver and kidney 3. fed state has excretion of urea and fasted excretes ammonium |
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Why is fasted and fed metabolism different |
-catabolizing alpha-ketoacid makes bicarbonate in krebs -so fed state encourages alkalosis -in fasted TAG breakdown makes acidic ketone bodies so NH4 passes urea cycle to spare the bicarbonate that would be used; more bicarbonate can be used to neutralize ketone bodies |
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Important AA in nitrogen Cycle |
-glutamate: accepts NH3 and can be an NH3 source, makes alpha-ketoglutarate aspartate: carreis nitrogen to urea cycle and makes oxaloacetate alanine: brings nitrogen to liver and makes pyruvate glutamine: carries nitrogen to liver and kidney and source of NH3 |
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4 reactions that move Nitrogen between organs |
1. transamination adds amino group to carbon skeleton to make ahpha-ketoacid and AA, uses B6 and pyridoxal phosphate, mos common are GPT and GOT 2. Oxidative deamination/glutamate dehydrogenase: realeases NH3 by making alpha-ketoglutarate and ammonium 3. glutamine production that takes in ammonium and then glutamate production that releases it 4. urea cycle where NH4+ from oxidative deamination and glutamate production becomes urea |
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Fat burns in flame of CHO |
-active krebs depends on avilability of oxaloacetate so gluconeogenesis is needed why glycogen is depleted -bc acetyl CoA from Beta ox needs to go to krebs |
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fed state |
-insulin secretion -glutamine and alanine carry nitrogen to urea cycle to prevent alkalosis by use of bicarbonate -urine is 90% urea |
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post-absorptive state |
-empty gut increases glucagon and lactate goes to cori cycle -alanine and glutamine carry nitrogen and urine is still mainly urea |
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fasted state |
-corticosteroid release increases protein catabolism and glucogenic AA make glucose in liver -fate starts to be be broke -alanine and glutamine both carry nitrogen but urine is 50/50 with urea to NH4+ |
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starvation state |
-epiephrine/catachloamine release spares protein loss and fat makes ketone bodies which promotes acidosis -glutamine carries nitrogen to kidney and urine is 90% ammonium |
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Seroid Hormone Receptors |
Ligand activated transcription factors -type 1: cytosolic that connect androgens and translocate to nucleus -type 2: Nuclear to steroid and non-steroid (A/retinoic acid, D/calcutriol ,iodine) |
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Iodine absorption |
-dietary can be free or bound to AA but is always converted to I- (found in body as this form) and absorbed in stomach -free I- in blood can permeate most tissues and goes into thyroid gland (stores 70-80%) through Na+/I- symporter (NIS) |
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iodine uptake |
dietary I- into GIT> absorbed into blood> NIS into thyroid> conversion to T3/T4> T4 goes to liver> 5'deiodinase (a selenoprotein) changes it to T3> T3 regulates metabolic rate through THR > T3 level detected by hypothalamus > secretion of TSH to regulate creation at thyroid gland |
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How Iodine Makes T3/T4 |
from blood to thyroid follicle cell through NIS> luminal side of cell secreted I- through pendrin and THG by exocytosis> I- is oxidized to I> I attacks Tyr residues on THG in thyroid lumen> iodated Tyr crosslink and this form can endosytose back into follicular cell> proteolysis makes thyrosine (T4) and triiodothryonine (T3) that are lipophillic and can cross membrane back into blood |
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thydroid hormone signalling |
-T3 binds to THR in nucleus to interact with response elements in promoter to activtae genes that increase metabolic rate (ATPase, growth hormones) effect on tissues: adipose (lypolysis), muscle (contraction), bone (anabolism), heart (increase rate), GIT (nutrient digestion) |
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Iodine deficiency |
=hyperplasia and hypertrophy to create groitter =cretinism =Iodine deficiency disease (IDD) which results in growth and development abnormalities |
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digestion and absorption of vitamin A |
-retinyl esters from milk and eggs remove fatty acid tail by retinyl esterase then absorbed -beta carotene from plants is absorbed and either converted to retinyl ester or incorporated to chylomicron -chylomicron reminent will bring both to liver where beta carotene is packed into VLDL and retinyl ester is stored in stellate cell -activity of beta carotene is determined by vitamin A status of the person |
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Vitamin Path through body |
retinyl esters in fat droplet from stomach cleaved to retinol by rentinyl esterase> fat droplet gives betacarotene and retinol to intestine through micell> in intestine beta carotene makes all trans retinal by 15,15 carotenoid monoxygenase> all trans retinal made to all trans retinol by retinol dehydrogenase OR 9-cis retinoic acid by retinoic acid isomerase> retinol made to retinyl palmitate by palmityl CoA> beta carotene and retinyl palmitate go into chylomicron that is cleaved by lipoprotein lipase to make chylomicron remnant> enters liver through receptor and beta carotene goes into VLDL to be stores in adipose as hypercarotenoids> retinyl palmitate is put into stellate cells for storage> retinyl esterase remakes retinol when needed which binds RBP to circulter to target tissue> taken up by receptor at target tissue then changed to retinoic acid which can act on genes through association with RXR (9-cis-RA) or RAR (trans-RA) and NHR |
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Direct use for Retinal |
-night vision -all trans retinol enters epithelial cell> conversion to 11-cis-retinal> moved to rod cell> makes rhodopsin> rhodopsin broken down by sunlight to release all trans retinal> changed back to all trans retinol> back to epithelial cell |
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Vitamin A deficiency |
-retinoic acid stimulates stem cell differentiation so deficiency leads to keratinization (makes karoten instead of mucous so bacteral infection occurs) 1. night blindnessfrom low rhodopsin/bitots spots from keratin build up in the eye 2. impaired epithelium differentiation 3. impaired growth from GH not being made 4. impaired fertility from low sperm production 5. fetal development defects |
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A requirements |
measured in RAE (retinol activity equivalents) -no UL bc beta carotene is stored in tissues -toxicity can lead to liver cell death from stellate cells overfilling |
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Sources of vitamin D |
1. plant souces with provitamin D2 2. natural animal sources with provitamin D3 (7-dehydrocholesterol) that can be activated to D3 (cholecalciferol) 3. sunlight makes vitamin D3 in skin that can bind to DBP (also makes lumisterol and tachysterol that are inactive but control D release by being shed or being converted back to 7-dehydrocholesterol; blocked by melanin 4. supplements for cancer prevention that include D3 and cholecalciferol |
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Active vitamin D |
SKIN: 7-dehydrochelesterol to D3 BLOOD: tranported by DBP ADIPOSE: storage LIVER: D3 (from blood as chylomicron remnant or DBP bound from diet) to 25OH-D to back to circulation on DBPby cytochrome p450 enzyme 25-hydroxylase which is NADH dependant KIDNEY: 25-OH-D to 1,25 OH2-D/calcitriol (stimulated by PTH) by 1-hydroxylase *1,25-OH-D acts on kidney bone or gut |
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calcitriol signalling |
genomic: VDR is a NHR so TF makes calcium binding protein which is then activated by vitamin k dependent PTM non-genomic: cell surface receptors MARRS trigger intracellular cascade of protein phosphorylation that acts quickly |
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cacitriol effect |
BONE: increase rank ligand release from osteoblasts to make osteoclasts increase activity and secrete factors that degrade bone matrix and release Ca and P into blood INTESTINE: genomic and non-genomic effects increase Ca binding protein, membrane transporters and MARRS activation KIDNEY: reabsorption to lower calcium excretion |
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hormonal control of calcium |
D/Calcitriol: increase blood calcium by resorption of bone, absorption at intestine and reabsorption in kidney PTH: first responseto activate 1-hydrxylase to make calcitriol Cacitonin: inhibitory version from parafollicular cells in thyroid |
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D deficiency |
-Rickets in infants -osteomalcia in adolescents and adults (fracture easily): demineralization -osteoporosis: middle aged/elderly where both bone components are eroded -toxicity (hypercalcemia) that makes soft tissue calcify |
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Vitamin K digestion and absorption |
-for bone formation and blood coagulation by making Ca2+ chelators -phyloquinone (saturated) from leafy greens is absorbed in jejumun through micells and menaquinone (unsaturated) made by bacteria is absorbed in colon -both go into chylomicrons for delivery |
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vitamin K cycle |
vit K quinone from diet>quinone reductase makes vit K hydroxy quinone (active reduced form) > gamma glutamyl carboxylase make vit K apoxidide (inactive oxidized form)> epoxidide retuctase to remake quinone -the gamma glutamyl carboxylase step makes a Gla residue on a blood clotting protein so it can bind phospholipids on platelets and endothelial membranes |
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vit K deficiency |
-in newborns bc non in milk and they don't have a microflora -antibiotic use malabsorptive illness -causes low blood clotting and low calcium binding which effects bone formation |
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calcium absorption |
-saturable carrier mediated transport regulated by calcirtiol in duodenum and jejunum -enters cells by TRVP5/6, carried across by calbindin, freed by PMCA1B, exits cell by NCX1 (also brings in 3 Na) -all increased by 1,25OH-D acting on nucleus increased by: PTH, pregnancy and lactation decreased by: caffine, fibre, megnesium, zinc |
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calcium functions |
-hydroxyapetite in bone -ionized to active form and used to make gla residue for blood clotting, sk muscle conrtaction, ion channel nerve potential, intracellular signalling pathway bc activates PLA2 to cleave AA from PL to make eicosanoids |
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calcium deficiency |
low bone mineralization=rickets, osteoporosis, osteomalcia muscles=tetany/ muscle contractions with no relaxation toxicity= constipation, bloating, gas |
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phosphorus |
-animal products as phosphorus and grains as phytic acid -inorganic form absorbed by passive diffusion in duodenum and jejunum (lowered by binders: magnesium, aluminium, calcium) -makes hydroxyapetite, central to metabolism, ket to protein phosphorylation |
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fluoride |
-makes fluoroapetite to protect teeth but otherwise non-essential -100% efficient passive diffusion in stomach -toxicity=mottling of teeth |
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Reactive oxygen species |
-H2O2 to H2O by glutathione peroxidase (selenium dependant) ideally: O2> H2O leakage: O2` > SOD makes H2O2 > GSH peroxidase makes H2O OR: H2O2 > OH` (will attack macromolecules) -SOD is the first line of defense in antioxidant response |
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Vitamin E types |
Tocopherols: (saturated phytyl tail) found free in food and absorbed passively (alpha tocopherol is active version that fits into transfer protein) Tocotrienols (unsaturated phytyl tail) cleaved by pancreatic esterase is needed for absorption and only have antioxidant activity in the liver |
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Vitamin E absorption |
-RDA based on RBC hemolysis in H2O2 presence
-UL bc it can cause bleeding but too low causes GI problems -deficiency in pre mature babies, pply with low fat absorption, no gall bladder, genetic defects in lipoprotein lipase or TTP -absorped in Jejunum using bile salts and NPC1L1 transporter then packed into chylomicrons to go to liver where TPP gets alpha-tocopherol packed into VLDL -stored in fat drops of adipose |
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Vitamin E Breaking Bad |
1) formation of radicals: avoided if GSH can make H2O2 into H2O 2) H2O2 makes Oh radical which reacts with PUFA in membrane 3) PUFA free radical made which reacts with O2 to make PUFA peroxy radical 4) lipid peroxidation cycle that can be intercepted by vitamin E to make PUFA hydroperoxide 5) PUFA hydroperoxide changed by FA peroxidase (selenium) to make PUFA alcohol; makes deadly short chain aldehyde if selenium not available *step 4 makes vit E radical that make make E dimer (bile), quinone (urinary excretion) or regenerate E (ascorbate/vit C) |
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selenium absorption |
-absorbed by AA transporters in small intestine then selenoAA travel freely in blood -30 selenoproteins in body that need it ex. glutathione peroxidase and FA peroxidase that both use GSH as substrate as a reducing agent (bc gamma peptide bond resistant to proteases) -in diet as selenomethionine (non-standard AA) or selenocyctein (proteogenic non-standard AA) -deficiency is kshan disease from free radical cell damage |
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Glutathione |
-gamma-glutamyl-cysteine-glycine -used by slenoproteins in vit E breaking bad -GSH=reduced (made by glutathione reductase that relies on B2) -GSSG=oxidized (made by GSH and FA peroxidase) -NADPH used to make GSH is regenerated by pentose monophosphate pathway/hexose monophosphate shunt which require niacin |
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Vitamin C/asorbic acid absorption |
-ascorbate at physiological pH taken in by sodium dependant vitamin C transporter (SCVT1 and 2) -mostly ascorbic acid in food that is changed -ascorbic acid (reduced) and dehydroascorbic acid (oxidized) are the two biologically active forms |
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Vitamin C uses |
Hydroxylation Reactions: post-translational, prolyl hydroxylase (to make proline OH on procollagen) becomes inactive ferric form after reaction and regenerated by ascorbic acid Oxidant defense: vitamin A presence lowers lipid peroxidation products in urine & deficiency increases GSSG |
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Vitamin C deficiency |
-hemorrhage, hair loss, loose teeth, swollen joints, poor wound healing (due to prolyl hydroxylase not being regenerated) |
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Niacin/B3 absorbtion |
-in food as nicotinamide, NAD, or NADP, in plants as provitamin nicotinic acid -glycohydroxylase releases free nicotinamide from NAD and NADP to absorb in SI through facilitated diffusion of nicotinic acid and nicotinamide nicotinamide=NAD precursor all tissues Nicotinic acid= NAD synthesis in liver -once NAD/NADP made niacin is trapped in cell and found in reduced form NADH or NADPH |
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NADP production |
two steps that can come from nicotinic acid or Trp: 2. build dinucleotide structure NAD: cartabolism NADP: anabolism deficiency: pellagra (dermatitis, dementia, diarrhea, death) |
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Riboflavin/B2 absorption |
-protein bound and released by HCl (FAD/FMV to free riboflavin) to be absorbed by sodium dependent RFT2 and transported in blood bound to albumin -stored in liver, kidney and heart |
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riboflavin metabolism |
FMN and FAD made in cells regulated by T3 activating flavokinase enzyme riboflavin > flavokinase makes riboflavinPO4/FMN > fad synthase makes FAD -these can be bound to enzymes to pass electrons (used in forming GSH) -deficiency=ariboflavinosis (fatigue, angular chelitis, inflammation of mouth and tounge, ulcers) common in people with thyroid disease bc they cannot make flavokinase |
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Thiamin/B1 absorption |
-free form in plants, TPP in animals: phosphate group is removed for absorption through thiamin transporters in jejunum and ilium -thiamin/plant provitamin > thiamin phyrophosphokinase regenerates TPP which is active form |
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thiamin in energy metabolism |
1. PDH complex: PDH-TPP goes onto pyruvate in decarboxylation step then replaced by CoA in transacetylatoin to make acetyl CoA; uses thiamin, pantothenic acid and riboflavin 2. alpha ketoglutarate dehydrogenase complex 3. trans ketolase pathway in hexose monophosphate shunt: role in NADPH production and ribose synthesis |
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thiamin deficiency |
deficiency sensitivity lowers with age -causes accumulation of lactate, pyruvate and alpha ketoglutarate Dry Beriberi: adults, muscle weakness and NS effects Wet Beriberi: children and teens, muscle weakness and NS effects Acute Beriberi: infants, anorexia, vomitting, lactic acidosis, eventually death |
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Pantothenic acid |
-all plants and animals absorbed passively in jejumun -tissue uptake through sodium dependent multivitamin transporter (SMVT) -4 phosphopantethine is active form for Fa sythesis (anabolic), CoA active form for oxidative reactions (catabolic) -acts in metabolism through active SH group pantothenic acid> 4 phosphopanthethine (add cystein and ATP) > CoA (add AMP) |
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Biotin |
-protein bound in food so proteolysis by pepsin cleaves it for absorption -free form absorbed -Has N ring (that can carry COO group) and S ring (that can bind to an enzyme through peptide bond) -used to transfer COO to another molecule (ex. pyruvate carboxylase binds biotin with peptide bond on lysine to pass carbon group to pyruvate substrate) |
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Folate/B9 |
folate=reduced form from food folic acid= oxidized form from fortified food -polyglutamines broken to mono by carboxypeptidase for absorbtion through PCFT in SI -needs Pterin ring, PABA, and glutamic acid to make metbolically active polyglutamic -found in blood as 5-methyl-THF -1 DFE=dietary folate equivalent =folate+1.7 folic acid -high levels increase cancer risk and mask B12 deficiency |
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Cobalamin/B12 absorption |
IF from gastric lining in stomach binds to make B12-If complex that can be absorbed in ilium -then broken down in enterocyte and B12 is stored in liver -group of corrinoids -deficiency leads to functional B9 deficiency or neurological degration (can be from low amounts in diet or IF problem so no absorption) |
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B12 Single Carbon Metabolism |
1. in SI B12 is un polyglutaminated and taken in as folic acid,B9 methylated to N5-methyl-THF with methyl from choline, serine or methionine 2. N5-methyl-THF enters bone marrow and methionine synthase makes THF using B12 as a cofactor 3. methyl B12 passes it to homocystein to make methionine for SAM (phosphatidylcholine, epinehprine, creatine, DNA methylation, drug metabolism) 4. THF gets a new methyl from serine aa to make N5N10-mehtyline-THF that can be reduced to return to SAM or make dTTP *therefore folate deficiency impairs DNA synthesis (megaloblastic anemia) |
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The Folate Trap |
only rxn to metabolize N5-methyl-THF is methionine synthase which depends in B12 -so B12 deficiency makes N5-methyl-THF trapped =functoinal folate deficiency -high folate can overcome this by saturating N5-methyl-THF so free folate goes to liver to make THF, by passes trap but doesn't support SAM -B12 deficiency=NTD/exposure of CNS |
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Vitamin B6 |
6 interchangable vitamers (pridoxine, pyridoxal, pyridoxamine and phosphorylated versions) -used in transamination by pyridoxal phosphate (PLP) so intake needs to be higher with a high protein diet -dephosphorylated for passive diffusion in jejunum and found in blood as PLP bound to albumin -pyridoxine> pyridoxal> pyridoxal phosphate which is coenzyme to make alpha keto acid -also in heme synthesis and neuroactive amine synthesis |
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types of anemias |
1. megaloblastic from problem with DNA synthesis (low folate and B12) 2. hemolytic form oxidant stress (low anti ox nutrients) 3. microcytic hypochromic from protein production problem (low B6) |
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Iron absorption |
Non-heme: HCl and proteases cleave from food in stomach to release ferric which is converted to ferrous by reductase (Fe2+) and absorbed by DMT1 Heme: stomach and Si proteases release from hemoglobin and prophrin ring goes into SI through HCP1 then heme oxygenase hydrolyzes to Fe2+ and protoporphrin -some will be stored by ferritin in enterocyte to be lost and rest exported by feroportin then ferooxidase makes Fe3+ to incorporate to transferrin |
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factors effecting iron absorption |
inhibitors: polyphenol from tea/coffee, oxalic acid in spinach, insoluble fibre enhancers: sugars, vit C (reducing agent and chelator with ferric), digestion products of meat, poultry and fish, soluble fibre |
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Iron digestion and metabolism |
-transported around body bound to transferrin as ferric form (3+) to prevent redox activity and bacteria binding -Fe2+ from ferroportin reacts with ceruloplasmin to make Fe3+ for transferrin which will carry to cells and release Fe2+ which will 1. go back to ferritin Fe3+ for short storage then hemosidderin Fe3+ for long storage 2. heme for cytochromes, hemo and myo globin 3. iron sulfur centers of iron metalloenzymes 4. reacts wil ceruloplasmin again to remake transferrin Fe3+ in plasma |
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iron level regulation |
-liver, bone and spleen for storage -liver sense transferrin Fe2+ and releases hepcidin to stop ferroportin so iron is stored in enterocyte for shedding -plasma trans-Fe3+ will go back to liver for storage, RBC synthesis in bone, reticuloendothelial cells in spleen to return heme to plasma -glyceine and succinylCoA > 5-amino leulinate by B6 > porphrin> heme by adding iron -catalase and thyroperoxidase are heme dependent enzymes |
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copper |
-component of enzymes: ceruloplasmin, cytochrome C, SOD, dopamine monoxygenase, tyrosinase -HCl and pepsin free from aa to be absorbed by CTr1 and DMT1 as Cu+ -enhanced by aa, organic acid, vit c and inhibited by antacids, phytic acid and zinc -high levels increase methalothiamine to hold in intestinal cell (so does phytic acid) -once in goes to liver to make ceruloplasmin for transport to other tissues |
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copper deficiency |
-anemia, hypopigmentation, bone abnormalities,menkes -toxicity is wilsons disease from built up copper (from ATB7B mutation) |
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ZInc Functions |
1. Zn containing metalloenzymes 2. in SOD 3. zinc Finger for DNA binding by shaping TF to bind to hstidine and cystein |
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Zinc absorption |
stomach acid and digestive enzymes to hydrolyze for SI absorption by ZIP4 (degrated by high zinc) -enhanced by organic acid and prostaglandin and inhibited by antacid, phytic acid and oxalic acid -in enterocytes for local use or sequestering, circulates bound to albumin deficiency=low growth, wound healing, sexual maturation, taste toxicity=copper deficiency by increasing metallothionine (neurlogical problems, numbness, metallic taste, nausea) |
