Electron Transport Chain Flashcards
what is the purpose of the ETC?
to finish the energy provision process by reoxidizing the cofactors produced by the TCA cycle
where does the ETC reside?
in the inner membrane of the mitochondira
where is ATP released into by the ETC?
into the mitochondrial matrix
another name for the ETC is?
respiration chain
The ETC is a stepwise process by which e- are carried from the ____ _____ to __
reduced cofactors to O2
the cofactors that are reduced in the electron transport chain are ____ by ___
oxidized by oxygen
what is the name of Complex I?
NADH dehydrogenase, NADH-CoQ-reductase
what is the name of complex II?
succinate degydrogenase, succinate CoQ-reductase
another name for Co-enzyme Q is?
ubiquinone
what is the name of complex III?
cytochrome b-c1 complex, ubiquinone cytochrome c reductase
what is the name of complex IV?
cytocrhome oxidase, cytochrome c oxidase
which three complexes to NADH/H+ go through?
I, III and IV
which three complexes to FADH2 go through?
II,III, and IV
another name for iron complexes?
cytochromes
what is the shuttle between complex I and III or complex II and III
CoQ (ubiquinone)
what is the shuttle between complex III and IV?
Cytochrome c
Why are only 2 moles of H+ channeled out at complex IV (as opposed to 4 at complexes I and III)?
The other two are used to generate one Mol of Water!
what is responsible for the different modifications of Fe2+/Fe3+ redox potentials?
the different biochemical environments
what is the only ETC carrier that is not a protein-bound cofactor?
ubiquinone
where in the body is a high concentration of ubiquinone found?
in the heart muscles
ubiquinone transports ___ through the ___ ____ into the ____ ___ of the mitochondira
it transports ptrotons through the inner membrane into the intermembrane space
which complex is the only component of the ETC that has a copper complex?
complex IV (cytochrome c oxidase)
which complex contains the binding cite for O2?
complex IV (cytochrome c oxidase)
the reduction of cytochrome by complex IV(cytochrome c oxidase) is coupled to what?
proton transport
the proton concentration inside complex IV is decreased by what two processes?
1- formation of water 2- outflux of protons by the complex
how many protons are transported into complex IV along with the the reduction of O2?
4 protons
the interaction between what two things reduce oxygen to water in complex IV?
the Fe and Cu complexes
heme, by definition if a cofactor containing what?
Fe2+
which complex is the only one that doesn’t involve the influx of protons that is then followed by their outflux?
complex II
since oxidation is always coupled with reduction, when the ___ ____ are oxidized then ___ is reduced
co-factors are oxidized, oxygen is reduced
what process it redox in the TCA paired with?
the phosphorylation of ADP to ATP
where does the energy used for ATP synthesis come from in the TCA cycle?
and proton-gradient across the inner mitochondrial membrane
can protons pass through the inner mitochondrial membrane?
no, the proton gradients is made by the ETC
the out-transport of protons by the ETC causes two kinds of gradients, what are they?
chemical (pH) and electrochemical (V)
The idea that energy for ATP synthesis arises from an H+-gradient across the inner mitochondrial membrane is known as what?
chemiosmotic theory
ATP synthase is made up of what tow main components?
a proton channel (F0) and an ATPase site (F1)
mitochondrial F1(ATPase) particles are required for __ ____ but not for ___ ___
ATP synthesis, proton transport
what subunit of the F1 (ATPase) unit rotates?
the gamma unit
when the gamma unit of the F1(ATPase) unit rotates it changes the shape of what?
the beta subunits
when the beta subunits are open in the F1 unit what happens?
ATP leaves and new ADP and Pi come in
what happens when the beta subunits in the F1 units are lose?
ADP and Pi bind together
what happens when the beta subunits in the F1 units are tight?
ADP and Pi react and form ATP
give an example of an uncoupler
DNP (dinitrophenol)
what do uncouplers, like DNP, do?
uncouple the ETC and ATP-synthases
what protein is located in the mitochondrial membrane of adipose cells and acts as a heat generator?
thermogenin
how many subunits for the ETC does mitochondrial DNA code for?
7
what are the 7 subunits that mitochondrial DNA encode for in the TCA?
1-complex I, 1- complex III, 3 - complex IV, and 2 for ATP-synthase
how many subunits are coded by nuclear DNA?
> 70
what is OXPHOS?
a genetic disease affecting oxidative phosphyrlation
what is a common cause of OXPHOS?
mutations of mitochondrial DNA, since the mitochondria doesn’t have repair systems as sophisticated as the nuclear DNA
where is creatine phosphate mostly found?
the brain, muscle and especially heart cells
what does creatine phosphate do?
acts as a buffer for ATP, by providing fast ATP generation via substrate level phosphorylation
