Oxidative Phosphorylation Flashcards
Oxidative phosphorylation occurs in the ???
matrix
the electron transport chain is embedded in the ??? of the mitochondria
the INNER mitochondrial membrane
Complex I is called ???
NADH dehydrogenase
Complex II is called ???
Succinate dehydrogenase
Complex III is called ???
Ubiquinone:cytochrome c
oxidoreductase
Complex IV is called ???
cytochrome oxidase
Complex V is the ATP synthase and is the ??? component of oxidative phosphorylation
phosphorylation
Which complex doesn’t do H ion pumping?
Complex II
Which complex(es)
exhibit Fe-S centers?
Complexes I, II, III
How many electrons do the complex(es)
exhibiting Fe-S centres carry?
1 electron (Ubiquinone by itself carries 2 e)
Name the amino
acid the Fe-S exhibiting complexes are bound to
Cysteine
TRUE or False: coenzyme Q (Ubiquinone) carries 2 electrons
True
What is the final e– acceptor of the ETC?
oxygen
Coenzyme Q (Ubiquinone) is ??? and can OR can’t freely diffuse within the
lipid bilayer of the inner
mitochondrial membrane?
lipid soluble, CAN freely diffuse
Coenzyme Q (Ubiquinone) Can OR Can’t shuttle reducing equivalents between other less mobile components?
It can
Cytochrome C is a soluble or insoluble heme-containing protein in the intermembrane space
soluble
Cytochrome C is a ??? carrier
mobile electron
Complex I to Complex IV reaction for NADH:
1 NADH, ???H (M) + ½O2 —> NAD+ + ???H+ (IMS) + H2
11 H+ ions to 10H+ ions
Complex II to Complex IV reaction for FADH:
FADH2 + ???H+ (M) + ½O2 —> FAD + ???H+ (IMS) + H2O
6H+ ions to 6H+ ions
What is the purpose of dehydrogenations of NADH, FMNH2, FADH2 and the reactions oxidising Coenzyme Q and Cytochrome C?
They pump protons (H+) into the
intermembrane space which is used to set up an electrochemical gradient
why is an electrochemical gradient set up?
to drive ATP synthesis
the FO component of ATP synthase is the ??? spanning domain
membrane-spanning domain
The FO component of ATP synthase transports H+ from IMS to ???,
dissipating the proton gradient.
matrix
the O in FO comes from ??? sensitivity.
oligomycin
Energy transferred from ??? to F1
to catalyze phosphorylation of
ADP
FO to F1
F1 component of ATP synthase is the ATP ??? domain and a soluble complex in the matrix
ATP synthesizing domain
In ATP synthase, A total of ??? H+ are transported per ATP generated by ATPase
A total of 3 H+ are transported
per ATP
TRUE or FALSE: An extra H+ is used by ATPase to transport phosphate (H2PO4- is required for ATP synthesis)
TRUE
Binding-Change model of ATPase: proton-motive force causes rotation of the ??? —the γ subunit
central shaft
ATPase: the γ subunit contacts each αβ subunit pair in succession.
= ??? which ejects ATP from the β-ATP site. The β-ADP site is converted to the β-ATP conformation, which
promotes condensation of bound
ADP + Pi to form ATP
conformational change
Oxidative phosphorylation can be discoupled by: ??? (such as digitonin), chemicals such as dinitrophenol, an uncoupling protein
disrupting membranes with detergents
Non-shivering thermiogenesis: The inner membrane of brown fat mitochondria is very permeable to H+ and UCPs allow H+ leak back across the inner membrane. Heat is produced instead of ???
ATP
UCP1 reduces the number of ??? that can be made from a given amount of food, raising the body’s
metabolic rate and generating heat.
ATPs
UCP2 is expressed in brain, fat, muscle, and b-cells of the pancreas. UCP3 is expressed mostly in ???
muscle
