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+--- Thread: Biochem! NBME 1 b1 q8 - roman736 (/showthread.php?tid=436681)
Biochem! NBME 1 b1 q8 - roman736 - ArchivalUser - 08-10-2009
In gout, hyperuricemia resulting from overproduction of urate is most likely to result from a lack of feedback inhibition by ADP or GDP at which enzyme?
a. Adenosine deaminase
b. Dihydrofolate reductase
c. Glucose 6-phosphate dehydrogenase
d. Nucleotide phosphorylase
e. Phosphoribosyl pyrophosphate synthetase
0 - ArchivalUser - 08-10-2009
d or e ??????? what d'ya think ?
8292 - ArchivalUser - 08-10-2009
I think it is E
0 - ArchivalUser - 08-10-2009
the answer is E. However, I have NO idea why and I posted this with the hope that someone will shed light on this topic.
0 - ArchivalUser - 08-10-2009
d is in the salvage pathway, while e is in the denovo pathway........ So ???
0 - ArchivalUser - 08-10-2009
According to FA p. 103(2008), Phosphoribosyl pyrophospate (PRPP) functions with HGPRT. Thus, an increase in PRPP due to decreased inhibition of PRPP synthetase should, in theory and by my calculations, NOT cause hyperuricemia because a decrease in those same pathways is what leads to Lesch-Nyhan syndrome.
But anyway, this might be one that I just let go and accept that i do not know it because there is a lot more high yield crap I gotta study right now before my exam!!!