© by nimmervoll michaela 10.09.2009 higher secondary school for chemical ingeneering 1 nimmervoll...
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ASCORBIC ACID
© by Nimmervoll Michaela
10.09.2009
Higher secondary school for chemical ingeneering
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The EU-Comenius Life-long-learning-program is financially granted by the European Commission.
INDEX History Properties Biosynthesis Adsorption and metabolic processes Function Determination
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HISTORY Remedy for scorbut 1747: James Lind Ascorbic acid – scorbut 1932: Waugh & King:
Hexuronacid 1933: Harworth & Szent-Györgyi:
Ascorbic acid
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PROPERTIES Withe crystalline substance Molecular weight:
179 g/mol Melting point:
190°C Water dissolves Effectivity:
D-Glucoascorbine acidVitamine A, E, B6, B12, K + Testosterone
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BIOSYNTHESIS Higher plants, most animals by D-
Glucose liver (mammals) kidney (birds, amphibian, reptils)
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ADSORPTION AND METABOLIC PROCESSES
Quickly in whole small intestine Pass cell mebrane (oxidized, lipophilic
form) Reduction to Ascorbic acid With circulation to organs Absorbing capacity: 1000mg
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FUNCTION Biochemical functions:
Hydrogen donator (electrons)Hydrogen acceptor (electrons)
Hold up body-functions:Sore cure and keloidSterotoninbiosynthesisSynthesis of THF and folic acidResistance infectious diseaseFerric resorptionRadical catcher
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DETERMINATION Materials:
Ascorbic acid2.6.-DichlorphenolindophenolOxalic acidChloroform testing tubes
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2.6.-Dichlorphenolindophenol Leuko - 2.6.-Dichlorphenolindophenol
DETERMINATION Implementation
Make 2.6.-Dichlorphenolindophenol (b=0,4 g/l)
Make ascorbic acid standard (b=2,5 g/l)2ml water in testing tube, and
0,5/1/1,5/2/2,5ml ascorbic acid+ small quantity oxalic acid+ 0,1ml 2.6.-DCPIPShake itWait 15 sec.+ 1,5ml chloroformadd step-by-step 2.6.-DCPIP till load transfer
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DETERMINATION
2.6.-DCPIP
blank sample
sample
sample
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SOURCES http://www.lebensmittelwissen.de/
chemie/ascorbinsaeure/eigenchaften-vitamin-c.php
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The EU-Comenius Life-long-learning-program is financially granted by the
European Commission.