EVERYTHING YOU NEED TO KNOW FOR METABOLISM 2 FINAL EXAM new stuff IF IT S NOT ON HERE IT S NOT ON THE TEST our TA review slides NOT posted on Bb as well as personal notes and tips Includes Water Soluble Vitamins Vitamin C and B vitamins o Required in small amounts o Not stored in body in large amounts o Excreted easily in urine to maintain balance o Only toxic in mega doses o Most involved in energy metabolism o She loves this chart So memorize it Tips for the final Our professor LOVES bones She does research and stuff on them So definitely read up on calcium vitamin d and osteoporosis information Know what grains are typically enriched with Thiamin Folate Iron and Niacin Our professor s daughter had hyperbilirubinemia it s discussed in the review slides so she will Know all of the conversion amounts such as the amount of niacin that can be made from probably ask a question regarding that tryptophan protein etc Vitamin B2 Riboflavin Part of 2 co enzymes involved in electron transport FMN flavin mononucleotide FAD flavin adenine dinucleotide Tri cyclic molecule which is easily phosphorylated to form FMN and FAD Mg2 or Mn2 is used along with ATP to convert riboflavin to FMN Mg2 or Mn2 along with ATP and FAD synthetase are used to convert FMN to FAD Digestion and Absorption Protein parts are removed by stomach acid and enzymatic hydrolysis FAD and FMN release their riboflavin part so that it can be absorbed The free riboflavin is then absorbed via active transport 95 It is phosphorylated again in the liver Predominant form in tissue is FAD Milk Dary grain products enriched meats NADPH is measured then FAD is added to re measure and determine Activity Sources Factor Vitamin B3 Niacin Generic name for nicotinic acid nicotinamide Goes through redox reactions NAD NADH Sources Meat and fish BEST Provide niacin as free nicotinamide NAD and NADP undergo hydrolysis both can be absorbed Other sources are cereals legumes seeds coffee tea Corn poor source Low in tryptophan Niacin is unavailable unless treated with lime water NAD can also be synthesized in liver from tryptophan 3 60 mg dietary tryptophan 1 mg niacin equivalent Functions 200 enzymes mostly dehydrogenases NAD Oxidative rxn s Glycolysis acetate oxidation in Krebs Beta Oxidation NADH electron transport from metabolic intermediates Produces ATP in ETC NADP hexose monophosphate shunt and malate shuttle NADPH reducing agent In FA synth cholesterol synth DNA precursor synth 14 NE day or 7 7 NE per 1000 kcal 1 NE 1mg Niacin 60 mg tryptophan 6000 mg protein DRI Deficiency THE 4 D S Dermatitis like sunburn Diarrhea nausea vomiting diarrhea or constipation Dementia neurological such as headache apathy memory loss paralysis delirium Death if untreated Population at risk People with higher energy requirements Drug interference Isonizid for TB Genetic disorders where some amino acids can t be absorbed such as tryptophan Hartnup disease Autosomal recessive metabolic disorder can t absorb tryptophan Nicotinic acid improves cholesterol by lowering LDL and VLDL while increasing HDL It releases histamine flushing can also cause skin and GI problems Also used to treat some mental disorders questionable now Assessment of nurtriture Measurment of N methyl nicotinamide in urine after a 50 mg test dose Urinary excretion of N methyl nicotinamide 5 mg g creatinine deficient 5 1 59 mg g creatinine marginal 1 6 mg g creatinine adequate Folate folic acid absorbed Multiple residues composed of pteridine PABA and glutamic acid All components must be present All components can be synth By body except coupline of pteridine with PABA Polyglutamate forms of folate need to be hydrolyzed to monoglutamate in digestion to be Catalyzed by gamma glutamylcarboxypeptidases or conjugases Zn dependent Zn deficiency may inhibit folate absorption Foods containing conjugase inhibitors legumes lentils oranges cabbage Within intestinal cells folate is reduced to active forms Tetrahydrofolic acid THF Dihydrofolic acid DHF Folate receptors found in several tissues Total body folate is 11 28 mg half is in liver THF Functions THF serves to transfer 1 carbon groups In synthesis of purines pyrimidines DNA RNA In metabolism of AA s glycine serine synth methionine regeneration histidine Sources DRI Green leafy veggies fruits legumes organ meats and yeast Raw foods higher in folate Easily destroyed by heating and processing Bioavailability varies Dietary Folate Equivilents DFE DFE microgram food folate 1 7 ug synthetic folate Synthetic folate has more bioavailability Deficiency Risk Poor diet Destroyed with freezing processing prolonged storage Intestinal malabsorption Alcoholics celiacs disease Inadequate metabolism Drug interactions Methotrexate Chemo Some antimicrobials Anticonvulsants Dilantin Those with increased demands Pregnancy Lactation B12 deficiency Folate Deficiency Megaloblastic macrocytic anemia Large immature erythrocytes Neural tube defects spina bifida anencephaly Possibly in beginning stage of cancer Status assessment RBC folate levels Plasma folate 160 800 ng mL show long term status methyltetrahydrofolte 6 25 ng mL shows short term status RBC and serum folate will depend on B12 Methyl folate trap Vitamin B12 Cobalamin Known as corrinoids corrin structure o 4 pyrrole rings attached together with Cobalt in center o Other groups can attach to Co to form 5 deoxyadenosylcobalamin 5 deoxyadenosyl group Methylcobalamin CH3 group Cyanocobalamin CN group Hydroxocobalamin OH group Aquocobalamin H2O Nitricobalamin NO2 group Absorption o Released from foods by pepsin in stomach o Free cobalamin attaches to R proteins which have high affinity for cobalamin These R proteins move cobalamin from sromach to small intestine R protein is hydrolyzed in duodenum cobalamin is released Intrinsic Factor IF synthesized in stomach binds to cobalamin in small intestine Complez travels to Ileum of small intestine where receptors are Transport present o After absorption cobalamin binds to a transport protein Transcobalamins TCI TCII TCIII Storage o Stored in liver 60 o Also in muscle 30 Sources Takes years to develop deficiency due to bacterial production o ONLY animal products as it originates from microorganisms 70 of B12 is retained after cooking Can be lost from milk after pasteurization not a good source Synthesized by microorganisms in our GI tract DRI o 2 4 2 6 ug day Functions o Serves as a coenzyme for many enzymes Metabolism of folate methionine synthetase For DNA synthesis
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