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 peroxisomes  




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Author16 Posts
  #1

what are peroxisomes involved in?

a)producing bile

b)making cholesterol

c)degrading purines

d)allof the above



  #2

d


  #3

D


  #4

d


  #5

its producing bile i think! and
they r involved in syn and degradation of hydrogen peroxide ,
beta oxidation of long chain fatty acidsand
phospho lipid exchange!!



  #6

B..


  #7

c ??


  #8

I'm sure about A, and D that happens in peroxisomes.

not sure about C, what I recall cholesterol and steroids are synthesized in SER .

Anybody knows more ?


  #9

I think it's A ....


  #10

Answer is A


  #11

can't be A since bile is made in the liver and stored in the gallbladder


  #12

D, sure abt synthesis of bile acid and cholesterol ( kaplan notes histo) for the purie synthesis had to llok up in net ,,and yes does purine catabolism also .so its D .


  #13

answer is A, not B as cholesterol is synthesized @ SER.


  #14

its A, in production of bile acid.....its involved in Beta oxidation of FA not in the synth of Cholesterol so it cant be B....so logically if one answer is incorrect.....it cant be option D that is All of above.

i hope that helps....plz do let us know if some 1 has other explanation.


  #15

Docs:

It is D.
Option A: I am sure all of us know that it is in the peroxisomes of the liver that bile acids are synthesized

Option B: Peroxisomes contain at least two enzymes necessary for the initial steps in cholesterol synthesis -- thiolase and mevalonate kinase. The rate-limiting enzyme in cholesterol synthesis, 3-hydroxy-3-methylglutaryl coenzyme A reductase, is also localized in peroxisomes

For option C: Xanthine, which is product in purine catabolism, is oxidized by oxygen and xanthine oxidase with the production of hydrogen peroxide. The urate is excreted and the hydrogen peroxide is degraded by catalase found in peroxsiomes. We just had to follow this pathway a little further..

So docs D is the right option.
Hope this helps

-- Dr. J . Iyer


Edited by janeiyer on May 05, 2010 - 11:21 AM

  #16

option C explanation is fantastic Dr. Iyer





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