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 Q Orotic acid  

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this forum seems dead! but my bio questions push me to post maybe some day some one some how knows the answers and cares to sharewink

a UW Q;patient 14 months yearold with high urine orotic acid and megaloblastic anemia ,,GIVING which one of these supplements would most likely benefits him?

1.folic acid





uridine,,,problem is in metabolism of orotic acid ,by giving uridine we make UMP -pyrimidine salvage-and UMP is an inhibitor of carbamoylphosphate synthase 2 so now less orotic acid is made.

my question ;why not folic acid?

nor kaplan neither FA talk about pyrimidine salvage pathways but i have seen 2 q on these,in UW! R THEY REALY IMPORTANT FOR EXAM??


This is on FA 2010 page 68 of Bichemestry section


oh my god


grin4- URIDINE WILL CAUSE NEGATIVE FEEDBACK TO CARBOMYL SYNTHASE SO NO MORE OROTIC WILL SYNTHSIZED,,THIS IS 1ST,,,,,,,,,,,,THE 2ND is uridine will continue steps of pathway distal to orotic steps,,,,,,thanks


First of all I want to say that the question is incomplete because it does not tell about hyperammonemia or BUN values so as to differentiate very imp. enzyme deficiencies.i.e. OTC(liver mitochondria) or 2 enzymes used in pyramidine synthesis.smiling face

I do agree with mohammen.
I WANT TO ADD THAT FOLATE IS REQUIRED IN dTMP synthesis in denovo Pyramidine synthesis.

Any more info is very welcome


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