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27 Cards in this Set
- Front
- Back
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dihydrofolate reductase inhibited by what |
Vitamin B9 (folic acid), Methotrexate and Raltitrexed |
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purines have what kind of structure? |
6,5 ring |
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purines are based on what |
uric acid |
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starting material in making purines |
ribose 5 phosphate |
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purines are constructed on what |
the ribose 5 phosphate ring |
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what is the end product of building purine on ribose 5 phosphate |
inosine monophosphate |
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what is added to inosine mono phoshate to make AMP |
NH2 at C6 position |
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what is added to inosine mono phoshate to make GMP |
NH2 at C2 |
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purine synthesis is inhibited by what |
end prodducts |
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pyridine ring structure |
6 membered ring |
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purine synthesis is |
not carried out on the ribose 5 phosphate ring |
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what is an early intermediate in pyridine synthesis |
PRPP |
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regulation(inhibition) of pyridine synthesis is |
end product inhibited |
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how do we make deoxyribonucleotides? |
Ribonucleotide Reductases whichoperate via a weird free radical mechanism |
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how do Ribonucleotide Reductases create radicals? |
using Fe3+ to extraction of an electron from Tyr122-> froms activated oxygen |
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what is the difference between uracil and thymine? |
thymine has a methyl group at the beside the carbonyl carbon |
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what enzyme adds the methyl group to thymine |
Thyamidilate Synthase |
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what does Thyamidilate Synthase use ? |
N5,N10-Methylene THF (tetrahydrofolate) |
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what is step 0 in Thyamidilate Synthase mechanism |
Generate iminium cationby breaking 5 membered ring,attack C6 of dUMP. Movesdouble bond to C5/C4 |
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what is step 1 in Thyamidilate Synthase mechanism |
Schiff-base-likegeneration of a Carbocation,electrophilic attack by dUMP |
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what is step 2 in Thyamidilate Synthase mechanism |
Extraction of proton,C=C at C5 of dUMP’ |
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what is step 3 in Thyamidilate Synthase mechanism |
NADH-like hydridetransfer to CH2 on C5 of dUMP’,electrons transferred back tocysteine on enzyme |
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Fluorouracil |
anticancer drug |
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what does fluorouracil do? |
irreversible inhibitor of Thyamine Synthase by preventing schiff base to attack the carbon... (it has a F at that carbon position |
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dihydrofolatereductase (DHFR) |
makes more N5,N10-Methylene THF (tetrahydrofolate) to generate more dTMP |
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purines are degraded to |
uric acid |
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what is gout caused by |
Gout is caused by UricAcid accumulation.Usually not a metabolicproblem |
