Question types

Start with

Question limit

of 51 available terms

Advertisement Upgrade to remove ads
Print test

5 Written questions

5 Matching questions

  1. Why IMP to GMP uses ATP
  2. Second Step in Pyrimidine biosynth ATCase
  3. Phophoribosyl transferases PRTs
  4. Why IMP to AMP uses GTP
  5. Tx of Gout with Allopurinol
  1. a Allopurinol is a suicide inhibitor of xanthine oxidase, because it is similar in configuration to hypoxanthine and it binds tightly to molybdenum in xanthine oxidase.

    Xanthine oxidase takes Hypoxanthine to xanthine and xanthine to uric acid
  2. b this is a way to use biofeedback high ATP means GMP should be formed Low ATP means ATP should be formed
  3. c Committed Step, and an allosteric enzyme

    Using Aspartate Transcarbamoylase, ATCase takes Carbamoyl Phosphate to N-carbamoyl aspartate adding aspartate
  4. d this is a way to use biofeedback high GTP means AMP should be formed Low GTP means GMP should be formed
  5. e Used for salvage

    Hypoxanthine Guanine PRT or HGPRT catalyzes 2 rxns

    PRPP and hypoxanthine to IMP plus PPi

    or PRPP plus Guanine to GMP plus PPi

    Adenine PRT , APRT

    PRPP plus adenine to AMP plus PPi.

5 Multiple choice questions

  1. IMP uses Aspartate and GTP to add N in place of carboxyl O at top

    Fumarate leaves leaving just NH2 and AMP is formed
  2. It lowers the PRPP pool by binding and using HGPRT to form an allopurinol ribonucleotide

    This inhibits the action of glutamine PRPP amidotransferase

    and Thus there is less flux through the de novo purine pathway
  3. serum urate decraeases
    serum hypoxanthine and xanthine increase, these are more soluble and easily excreted
    Decreases total rate of purine biosynthesis
  4. UMP plus two ATP becomes UTP
  5. AZT, DDC, ddI
    Used to treat HIV and AIDS
    Triphosphates inhibit retroviral reverse transcriptase

5 True/False questions

  1. Sixth step OMP decarboxylaseAZT, DDC, ddI
    Used to treat HIV and AIDS
    Triphosphates inhibit retroviral reverse transcriptase


  2. Glutamine PRPP amido transferaseThe most important step, most difficult thermodynamically, and committed step.

    goes from PRPP to PRA

    Takes nitrogen from Glutamine and places on ribose with a PPi leaving group and Glucose formed


  3. Ribonucleotid Reductase relates to SCIDS byhigh conc of dATP stops the enzyme and other dNTPs are not made


  4. Eukaryotic Regulation of Pyrimidine BiosynthCTP inhibits two enzymes

    CTPS which forms CTP from UTP is inhibited by CTP, also it requires GTP so low GTP will slow CTP formation

    CPS II is the first reaction which forms carbamoyl P, and is inhibited by CTP


  5. HypoxanthineClinical use of nucleotide analogs usually is restricted to bases and nucleoside since phosphorylated nucleotides are poorly transported into cells

    They rely on tricking cellular or viral enzymes into phosphorylating nucleosides into metabolically active nucleotide forms, or converting bases into nucleotides vis salvage pathways


Create Set