purine metabolism

  1. what is the difference between ribonucleoside and ribonucleotide
    • ribonucleoside: base+ribose
    • ribonucleotide: base+ribose+phosphate group
  2. give an example of ribonucleotide
    AMP, GMP, CMP, UMP
  3. what is PRPP catalyzed by
    PRPP synthetase
  4. what is the first purine formed in the purine metabolic pathway
    inosinic acid (IMP)
  5. 3. what is the
    IMP + Aspartate + GTP --> ?

    what is the enzyme that catalyzes this reaction
    • adenylosuccinate
    • enzyme: adenylosuccinate synthetase
  6. what is
    adenylosuccinate --> AMP + ?

    enzyme that catalyzes this reaction
    • fumarate
    • enzyme: adenylosuccinase
  7. IMP+ NAD --> ? + NADH + H

    and enzyme that catalyzes this reaction
    • XMP
    • enzyme: IMP dehydrogenase
  8. XMP + ? + ATP --> GMP + ? + AMP + PPi
    • glutamine
    • glutamate
  9. what molecule activates PRPP amidotransferase
    PRPP
  10. what molecule inactivate PRPP amidotransferase
    IMP, GMP, AMP
  11. what do AMP, GMP competitively inhibit?
    • AMP: adenylosuccinate synthetase
    • GMP: IMP dehydrogenase
  12. GTP is required for ___ synthesis 
    ATP is required for ___ synthesis
    • GTP --> AMP synthesis
    • ATP --> GMP synthesis
  13. what are the molecules required for regulating purine biosynthesis
    • PRPP amidotransferase
    • AMP
    • GMP
  14. what are the enzymes involved in purine degradation
    • nucleotidase: purine mononucleotide + H2O --> purine nucleoside + Pi
    • deaminase: adenosine + H2O --> inosine + NH4
    • purine nucleoside phosphorylase: inoside + Pi --> hypoxanthine + R1P; guanosine + Pi --> guanine + R1P
    • guanase: deaminates guanine -->xanthine
    • xanthine oxidase: hypoxanthine --> xanthine --> uric acid
  15. what are the cofactors for the degradation of purines
    • Mo
    • Fe3+
    • FAD
    • O2
  16. how can purine be salvaged
    reconverting nucleosides to nucleotides via nucleotide kinases
  17. what is the disorder caused by deficiency of HGPRT
    • lesch-nyhan syndrome which is an X-linked mutation, thus limited to males.
    • characterized with aggressive behavior that leads to self mutilation
  18. what is gout caused by
    increased uric acid or decreased renal excretion
  19. what is the treatment of goat
    • allopurinol
    • competitively inhibits xanthine oxidase and reduces the formation of uric acid.
    • decreasing the formation of kidney stones
Author
tanyalequang
ID
343384
Card Set
purine metabolism
Description
the metabolism of purine bases A,G
Updated