dxtxpx
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The drug 5-fluorouracil (5FU) is a potent antimetabolite used for CA chemotherapy
I) which enzyme is inhibited by this drug?
a) DNA polymerase
b) thymidine kinase
c) reverse transcriptase
d) thymidylate synthetase
e) HGPRT
II) Which compound would accumulate in 5FU treated pts?
A) dTMP
b) dUMP
c) hypoxanthine
d) xanthine
e) ATP
III) 5FU works as CA chemo agent by
a) depolymerizing microtubules
b) preventing microfilament assembly
c) arresting mitosis at metaphase
d) blocking DNA synthesis
e) blocking DNA transcription
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| asmi
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1.d
2.A
3.B
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| dxtxpx
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only 1 is correct
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| asmi
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2.B
3.A
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| alice8
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d) thymidylate synthetase
b) dUMP
d) blocking DNA synthesis
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| dxtxpx
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1) d
II) b
III) d
5FU is a pyrimidine analog. After activation to mucleotide level by salvage pathways, 5FU is converted to FdUMP which is a potent inhibitor of thymidylate synthetase. When thymidylate synthetase is inhibited, DNA synthesis is blocked and cell divison is not possible. 5FU can also be converted to FUTP which will subsequently be incorporated into RNA, perhaps explaining some of non-specific cytotoxicity of 5FU. Thymidine and uridine are both required to rescue 5FU treated cells
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| asmi
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THANKS DX...
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| asmi
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WHAT IS COMMON BETWEEN METHOTREXATE AND 5-FU ?
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