Vitamins Food sourcesStability Forms Digestion/absorption Pathways/rolesThiamin B1Meat (esp pork), legumes, enriched whole grain bread/cereal productsWater soluble (susceptible to destruction), not stable in alkaline or heatPlants- free thiaminAnimal products= coenzymes: Thiamin diphosphate (TDP) and thiamine pyrophosphate (TPP)-Eaten in all formsfree thiamin:-low conc: active transport w/ sodium-high conc: passive-intestine: phosphorylated thiamin free thiamin; via phosphatase inside enterocyte:-can be phosphorylated and used in coenzyme form-leaves by active transport transport in blood:-use in vitamin form-90% transported in RBCs-rest bound to albumin in plasmaTissues:-thiamin must be phosphorylated to turn into active (coenzyme) form-TPP and TDP is found in skeletal muscles, kidneys, liver, CNS-starts w/ acetyl coA and ends w/ succinyl (?)coenzyme roles:- pyruvate dehydrogenase complex -a-ketoglutarate dehydrogenase complexbranched chain a-keto acid dehydrogenase complex (broken down in muscle, maple syrup disease)-indirect E production in all three-we also use thiamin in MEOS pathway-HMP-shunt: which makes NADPH and FA and cholesterol synth. (trasnketolase enzyme is thiamin dependent)synaptic fnc:-TPP released by synaptosome after action potential- TPP may also be needed for NA+ channel fnc b/c it is a phosphate donorB2- riboflavinDairy products, meat, eggs, legumes, green veggies, enriched Consists of: -ribitol side chain and flavin (isolloxazine rings)derivatives:-FMNEaten in all forms: -riboflavin (meat, animal sources, plants)-FAD and FMN (mostly animal)riboflavin phosphate (plant and animal)stomach:FAD as a coenzyme:- krebs: succinate fumurate via succinate dehydrogenase -accepts H+ then donates to energy (used twice after complex I, makes 2 atp), FMN is used by complex I of ETC-pyruvate acetyl coa (makes 3 FADs in 2cereals and grains-FADvitamins are way smaller than coenzymes. We usually transport in vit form freed from proteins by HCL and gastric enzymesintestines:- riboflavin freed from protein by intestinal enzymes-FAD and FMN converted to ribo b/c we want vit form for transportFAD FMN riboflavin-riboflavin phosphate hydrolyzed by phosphatases by riboflavin-absorbed in proximal S. intestine (rate proportional to dose)-large amounts-passive, small-active -riboflavin enters portal systemblood:-riboflavin, once in liver converts to coenzyme formsFAD, FMN bound to albuminTissues:-free ribo absorbed at most cells, and then once inside converts to coenzymeshidden rxns involving dihydroipolyl)-same as above for a-ketoglutarate succinyl coA-B-oxidation: riboflavin converts to FAD that accepts an H+ to turn fatty acyl coA to enoyl coAroles:-meurotransmitters: deanimation of nuerotransmitters uses the enzyme monoamine oxidase which requires FAD-vitamin b6 metab requires FAD and FMN: pyridoxial to pyridoxic acid-folate metab requires FADH2-synthesis of niacin from tryptophan requires FAD-glutathionine GSH: glutathionine reductase requires FADNiacin b 3Fish: tuna halibutMeat: chicken, beef, turkey, pork.Enriched cereals.breadsAlso synthesized in the liver by trptophan (60 mg trp: 1 mg B3 ratio); not enough for all body fncs 2 vitamin forms:-nicotinic acid: niacin-nicotinamide: nicainamide*these two can be interchangeable in body *absorbed in small I2 coenzyme forms:-NAD-NADP*have to be present for vitamin to fncEaten in all 3 forms:- nicotinic acid: plants -free nicotinamide -NAD-NADP-NAD and NADP have to be broken down to vitamin form (hydrolyzed in intestines to free nicotinamide via glycohydrolase)small intestine:-nicotinamide absorbed here -low concentrations sodium dependent facilitated diffusion - high conc passive diff-transported in blood to tissues -nicotinamide serves as precursor to NAD and NADP in tissue cells-nicotinic acid serves as precursor to NAD in cells and nicotinamide in liver *break it down from coenzyme to vitamin in blood, and then once its in the cell, you reform it into coenzyme (functional form)* once its in the cell:- if NAD accepts H+ and donates to ETC-if NADP reducing agent for synthesis pthwy. i.e) FA and cholesterol synth- niacin is involved in 200 enzymes that require the coenzymes NAD and NADPNAD:-Coenzyme for dehydrogenase-involved in:1) glycolysis (glycaldehyde 3 phosp 3p 1,3-biphosphoglycerate via g3p dehydrogenase)2) pyruvate acetyl coa via pyruvate dehydrogenase3) krebs (isocitrate dehydrogenase, alpha-ketoglutaratedehydrogenase, malate dehydrogenase)4) B oxidation (B-hydroxyl coa dehydrogenase5) oxidation of ETOH (alcoholdehydrogenase, acetaldehyde dehydrogenase)energy production ETC-Each NADH makes 3 ATPs-complex I: NADH dehydrogenase complex (NADH NAD)-complex 1III is transported by ubiquitone (Q)-complex III: proton pump-complex IV: proton pump -ATP synthase: pumps proton into matrix to form ATPDNA:-NAD donates diphosphate ribose and attaches it to a protein to form cyclic ADP ribose -main player in formation of structure of DNA-cyclic ADP ribose plays a part in DNA repair replication and cell differentiationNADP- formed into NADPH in the HMP shunt:-NADPH is then use in these rxns:-FA synthesis, cholesterol synthesis, folate metab, alc metab (MEOS)Pantothenic acid B5Meats (esp liver), egg yolk, legumes, whole grain cereals potatoes, mushrooms, broccoli, avocados, royal jelly Forms:- pantothenic acid (pantothenate), is usually bound to coA (part of the actual structure)-panthothenol, alcohol form, fond in multivitamins -eaten in free and bound forms -85% as part of CoA-CoA pantothenic acid, via phosphatasesintestines-jejunum (low concentrations-sodium dependent multivitamin transport (SMVT), high- multivitamin carrier)blood:-extracellular: free in plasma-intracellular: in erythrocyte Tissues:-functions as CoA, 4’phosphopantetheine, and acylation factorsB 4’-phosphopantothenic Fatty acid synthase complex:- dimer of 2 polypeptide monomers-fatty acid chain elongation-acetyl coa malonyl coa chain elongation via FA synthase-transfer acyl groups acetylationcholine acetycholine (neurotransmitter)-pantothenate 4’-phosphopantothenate, (4’ phosphor) pantethiene CoA-pathway inhibited by acetyl coa, malonyl coa, other acetyl coa-From CoA we can form acetyl coA, malonyl coA, propionyl coA, methylmalonyl coA, succinyl coAcoA is involved in:- decarboxylation of pyruvate, -decarboxylation of a-ketoglutarate-acetyl coa + acetoacetyl coa= HMG CoA which makes
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