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 METABOLIC PATHWAY posted by pallav  

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Author8 Posts

but inspired by muzammil!

here's my summary

an underweight 4 yr ol boy presents semi comatose . plasma glocose urea and glutamine are abnormally low

acetoacetate is elevated.
lactate is normal
he is admited to the icu where an ncrease in blood glucose was achieved by controlled infusion of glucagon or alanine
which metabolic pathway is most likely deficient in this child

a hepatic gluconeogenesis

b sk muscle glycogenolysis

c adipose tissue lipolysis

d sk muscle proteolysis

e hepatic glycogenolysis

HYPERKETONEMIA meansadipose tissue lipolysis(C) is normal

in the differentials of HYPERKETOTIC hypoglycemia there are two main differentials

defects in Gluconeogenesis, either

1) in the process it self. this may be due to enzyme deficiency

2)provision of substrates for gluconeogenesis

alanine infusion restores sugar levels. hence 1) is ruled out

D is the likely option. low glutamine and plasma urea levels support this answer. normally when muscle proteins are broken down, we use the carbon skeletons and transfer their amino group to Alanine and glutamine. these r deamnated in the liver and kidney to produce urea.


kudos to studying

although i just hate you

but its a beautiful explanation

keep up

there are some people i love to hate





good job study-ing. nice explanation. thank you. we are certainly not in the same bioch league.


please tolito...u have no idea how dumb struck i was by this negative cognition before the exam..( it took me a lot of time to 1)understand it and then write it) fact thats y i wrote it...coz i found it so difficult


ok study-ing, i was gingered up to read it and understand it. my approach is similar to yours but with less detail.

A adn E are out cos glucagon restored sugar level
B is out cos muscle glycogenolysis does not affect blood sugar level
C is out cos there is high acetoacetate which is derived from fa breakdown.

only option left is D. we know that lactic acid from muscle activity and alanine from muscle breakdown are substrates for glucogenesis. via cori and alanine cycles resp. the low levels of alanine and urea are in support of D.


but no question regarding who has put greater amount of heart into the question


I have a question

why not E/hepatic glycogenolysis????? I see that D is a good answer but I cant understand why a glycogenolysis impairment couldn.t be also a good answer...


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