peekay
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1-INCLUDE ALL OF THE FOLLOWING EXCEPT
A-ANTIMYCIN A
B-SODIUM AZIDE
C-CYANIDE
D-DINITROPHENOL
E-AMYTAL
2- WHICH OF THE ABOVE SITE SPECIFIC INHIBITORS BLOCK THE ETC AT A STEP WHERE ONLY ONE ATP IS GENERATED.
3- IN OXIDATIVE PHOSPORYLATION, UNCOUPLERS SUCH AS ASPIRIN , WHEN GIVEN IN HIGH DOSES, CAUSE HIGH FEVER BY BLOCKING WHAT MECHANISMS?
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| asmi
Forum Hero
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1. amytal
2
..2,4 dinitrophenol
3.inhibition of kreb's cycle and uncoupling of oxidative phosphorylation .
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| Bela
Forum Guru
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In ur first q, all the answers look site specific, according to what I've read in first aid. The pneumonic is BAR DACO
NADH dehydrog blocker: Barbs, Amytal, Rotenone
Blockage of Q(ubiquinone): Doxorubicin
Complex 3(cytoch bc1): Antimycin A
Complex 4(cytoch aa3): Cs (CO, CN, Azide)
Mitoch ATPase: Oligomycin
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| peekay
Forum Guru
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dinitrophenol is not a site specific inhibitors, it abolishes the electron gradient hence does not block any of the sites in ETC. Lippin biochem has a picture of this mechanism
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| asmi
Forum Hero
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ok so dinitrophenol is not site specific....are you sure peekay ?
What about the answer to your 3rd Q ?
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| peekay
Forum Guru
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MOA of uncouplers:increase the prmeability of the inner mitochondreal membrane to protons.
Electron carriers such as 2,4 DNP and aspirin cause diffusion of proton across IMM as a result more energy in the form of ATP is produced which lead to fever( increaded heat from energy)
Flow of proton that is (H+) is from cytosolic side of IMM to matrix side of IMM.
[/b]
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| usmle prep
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WHAT IS THE ANS. OF Q2??
IS IT OLIGOMYCIN??
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| Waziri
Forum Junior
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The mechanism of Fever formation is not because of more ATP production. Rather the ATP formation is inhibited by the uncouplers like ASA and Dinitrophenol which cause the energy to escape as heat producing the fever.
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| usmleasr
Forum Guru
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oligomycin inhibits ATP synthase
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| usmle prep
Forum Senior
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thats the only step in ETC,where one ATP is generated;
INHIBITION OF ATP SYNTHASE,so the ans of Q 2 should be OLIGOMYCIN.
plz correct me,if i am wrong??
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| peekay
Forum Guru
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REDUCED SUBSTRATE --->NAD--->FMN--->CoQ---->C yto c-----
THERE IS ATP GENERATED FROM ATP, SO IF CONVERSION OF FMN TO CoQ
IS BLOCKED THAN THERE WILL BE ATP ONLY FORM FMN .AMYTAL AND ROTENONE ACT AT THIS STEP.SO THE ANSWER IS AMYTAL FROM THE GIVEN CHOICES.
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| asmi
Forum Hero
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peekay can you give the answers again for all the three Q's you asked .
thanks
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| peekay
Forum Guru
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1-D
2-E
3-MOA of uncouplers:increase the prmeability of the inner mitochondreal membrane to protons.
Electron carriers such as 2,4 DNP and aspirin cause diffusion of proton across IMM as a result more energy in the form of ATP is produced which lead to fever( increaded heat from energy)
Flow of proton that is (H+) is from cytosolic side of IMM to matrix side of IMM.
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| step1taker
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hi peekay 
why is E the answer in # 2?
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| usmle prep
Forum Senior
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thats what i am ALSO asking??
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| bright_nnn
Forum Senior
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Ans 1=D B/c Dinitrophenol is the only one that an Uncoupler
Ans 2 = dont know how it is E.Because it is not FMN passing the e- it is the FAD(how will Fad block produce only one ATP since its blockade would stop the whole process of passing the e- finally to the Oxygen
Ans 3=It is definitely like waziri says that the Uncoupler like Nitrophenol,Asprin and Thermogenin cause more heat to be released as Heat by making the Inner mit. Mem. leaky to protons =decreasing the poon gradient
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| bobby
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Posts: 569
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about the same topic,
what inhibits ATP/ADP translocase of the ETC
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| usmle prep
Forum Senior
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oligomycin
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| bobby
Forum Guru
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Posts: 569
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the correct ans is; Atractyloside
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