Stability Forms Digestion absorption Pathways roles Plants free thiamin Eaten in all forms Vitami ns Thiami n B1 Food sources Meat esp pork legumes enriched whole grain bread cerea l products Water soluble susceptib le to destructio n not stable in alkaline or heat Animal products coenzymes Thiamin diphosphate TDP and thiamine pyrophosphate TPP free thiamin low conc active transport w sodium high conc passive intestine phosphorylated thiamin cid 224 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 plasma Tissues 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 complex branched 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 donor B2 ribofla vin Dairy products meat eggs legumes green veggies enriched Consists of ribitol side chain and flavin isolloxazine rings derivatives FMN Eaten 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 cid 224 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 cid 224 acetyl coa makes 3 FADs in 2 cereals and grains FAD vitamins are way smaller than coenzymes We usually transport in vit form 2 vitamin forms nicotinic acid niacin nicotinamide nicainamide these two can be interchangeable in body absorbed in small I 2 coenzyme forms NAD NADP have to be present for vitamin to fnc Niacin b 3 Fish tuna halibut Meat chicken beef turkey pork Enriched cereals brea ds Also synthesized in the liver by trptophan 60 mg trp 1 mg B3 ratio not enough for all body fncs freed from proteins by HCL and gastric enzymes intestines riboflavin freed from protein by intestinal enzymes FAD and FMN converted to ribo b c we want vit form for transport FAD cid 224 FMN cid 224 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 system blood riboflavin once in liver converts to coenzyme forms FAD FMN bound to albumin Tissues free ribo absorbed at most cells and then once inside converts to coenzymes Eaten 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 hidden rxns involving dihydroipolyl same as above for a ketoglutarate cid 224 succinyl coA B oxidation riboflavin converts to FAD that accepts an H to turn fatty acyl coA to enoyl coA roles 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 cid 224 GSH glutathionine reductase requires FAD 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 cid 224 accepts H and donates to ETC if NADP cid 224 reducing agent for synthesis pthwy i e FA and cholesterol synth niacin is involved in 200 enzymes that require the coenzymes NAD and NADP NAD Coenzyme for dehydrogenase involved in 1 glycolysis glycaldehyde 3 phosp 3p cid 224 1 3 biphosphoglycerate via g3p dehydrogenase 2 pyruvate cid 224 acetyl coa via pyruvate dehydrogenase 3 krebs isocitrate dehydrogenase alpha ketoglutaratedehydrogenase malate dehydrogenase 4 B oxidation B hydroxyl coa dehydrogenase 5 oxidation of ETOH alcohol dehydrogenase acetaldehyde dehydrogenase energy production ETC Each NADH makes 3 ATPs complex I NADH dehydrogenase complex NADH cid 224 NAD complex 1 cid 224 III is transported by ubiquitone Q complex III proton pump complex IV proton pump ATP synthase pumps proton into matrix to form ATP DNA 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 differentiation NADP formed into NADPH in the HMP shunt NADPH is then use in these rxns FA synthesis cholesterol synthesis folate metab alc metab MEOS B 4 phosphopantothenic Fatty acid synthase complex dimer of 2 polypeptide monomers fatty acid chain elongation acetyl coa cid 224 malonyl coa cid 224 chain elongation via FA synthase transfer acyl groups acetylation choline cid 224 acetycholine neurotransmitter Pantoth enic acid B5 Meats 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 cid 224 pantothenic acid via phosphatases intestines 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 factors pantothenate cid 224 4 phosphopantothenate 4 phosphor pantethiene cid 224 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 coA coA is involved in decarboxylation of pyruvate decarboxylation of a ketoglutarate acetyl coa acetoacetyl coa HMG CoA which makes cholesterol and bile acids fatty acyl CoA to enoyl CoA is in B oxidation Malonyl CoA is involved in FA synthesis
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