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Flashcards in electron transport chain Deck (21)
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what component of the chain is affected by CN-?

complex 4
cyanide blocks the transfer of electrons to oxygen by complex 4


what the components of Proton motive force?

the difference in pH and charge
so blocking the transfer of charge will not completely dissipate the proton motive force


Equilibrating the proton gradient across the inner mitochondrial membrane will

destroy the proton motive force


How would a deficiency in iron affect the ETC?

there will a deficiency in Fe-S centers that would impair the transfer of electrons down the chain and reduce ATP production by oxidative phosphorylation


what would be expected of a pt with a OXPHOS disease?

A high NADH/NAD+ ratio in the mitochondria
NADH would be reoxidized efficiently
the ADP:ATP ratio would build up


What carries electrons in the inner mitochondrial membrane?

CoQ, this is the Q pool


What molecule relays electrons between complex 3 and 4?

Cytochrome c


what is complex I also called?

NADH ubiquinone oxidoreductase


what is complex 3 also called?

ubiquinol cytochrome c oxidoreductase


what is complex 4 also called?

cytochrome c oxidase


what accepts electrons from complex 4?



what performs oxidative phosphorylation?

ATP synthase


what do uncouplers do?

disrupt the proton gradient by allowing protons to pass across the membrane more easily
this generates heat but no energy


what is ATP - ADP translocase?

mediates the movement of ATP and ADP across the mitochondrial membrane
ATP movement out is favored because the cytosol is + relative to the - matrix
ATP out and ADP in is a net movement of negative charge out which equals an H+ going in
so ATP out costs one H+
and synthesis of ATP costs about 3 H+
so total moving ATP out costs 4 H+


NADH cannot cross the mitochondrial membrane, so how are electrons of cytosolic NADH fed into the electron transport chain?

Shuttle systems
specifically the malate-OAA-aspartate shuttle
malate and aspartate can cross the mitochondrial membrane
In the cytosol, OAA converted to Malate consuming an electron from NADH, malate crosses the membrane and is converted back to OAA thus recovering the electron on an NADH
To move electrons out, OAA is converted to aspartate which crosses and is converted back to OAA


what is aspartate anti-transported with across the mitochondrial membrane ?

Glutamate which is generated from a-ketoglutarate
Glu moves into mitochondria where it is converted to a-ketoglutarate
Aspartate is moved out at the same time


What is anti transported with malate, as malate moves into the mitchondrial matrix?

which moves out to the cytosol while malate moves in
in the cytosol, it is converted into glutamate to assist in moving aspartate out of the mitochondria


Release of cytochrome c from mitochondria is one signal for



Reperfusion injury

when O2 returns, get burst of ROS due to O2 reacting with many reduced CoQ, cytochromes and flavins


what would upregulated the TCA cycle?



what is the toxic effect of CN- ?

binds the heme in complex 4/ cytochrome c oxidase blocking its ability to move electrons to oxygen