Chapter 20 (Oxidative Phosphorylation) Flashcards
The free energy released ETC is conserved by the creation of a ___ across the ___ which is an (exer/ender)gonic process
proton gradient
inner mitochondrial membrane
endergonic
Pumping 1H+ out takes about ___kJ/mol, the release of 2e- from NADH generates about ___kJ/mol so NADH can release ___ H+
20
200
10 (from 200/20)
The dissipation of the proton gradient is an (exer/ender)gonic process
exergonic
ATP is synthesized via the enzyme ___
ATP synthase (Complex V)
ATP-ADP exchange
ADP and Pi will become ATP without a proton gradient however it will break back down
We need the proton gradient to release the ATP so it will not breakdown
(T/F) ATP synthase can run in both directions
True
ATP-synthase is also called
F1-F0-ATPase
F0 subunit
Water insoluble transmembrane (bound in membrane) proton channel
Contains the rotor
F1 subunit
Water soluble peripheral membrane
Contains the Rotor shaft and Stator
The (F1/F0) subunit contains greek letters
F1
The ___ subunit is a rotor that turns in the membrane with respect to the ___ subunit
c
a
(refers to F0 because of normal alphabet)
Protons entering the a-subunit inlet channel are transferred from an ___ to an ___ located at the midpoint of a ___ subunit
Asn
Asp
c
The c subunit rotates ___ to bury the protonated ___ into the hydrophobic membrane
clockwise
Asp
The ___ remains protonated until it comes into contact with the ___ subunit outlet channel where the proton is transferred to a ___
Asp
a
Ser
pH > pka = (protonated/deprotonated)
deprotonated
F1 has (#) catalytic protomers
3 (alpha beta subunits)
The ___ and ___ subunits are the only ones that move in ATP-synthase
gamma and c
The gamma subunit of ___ is (hydrophobilc/philic)
F1
hydrophobic (makes turning smoother)
L
not catalytically active, binds ADP and Pi
T
catalytically active, binds ATP
O
a low affinity for substrate
The conversion of L to T results in:
synthesis of ATP
The conversion of T to O results in:
release of ATP
___ ATP are synthesized per one complete turn of the ___
3
gamma subunit/ c ring
The # of subunits in the c-ring vary from ___ (vertebrates) to ___ (prokaryotes)
8
15
It requires ___ protons per ATP synthesized
3
P/O ratio for NADH
2.5
P/O ratio for FADH2
1.5
High [ATP] or low [ADP] leads to (increased/decreased) respiration
decreased
Electrons will only flow to O2 when there is a supply of ___
ADP
We need both ___ and ___ for ATP synthesis to occur
e- and ADP
Uncouplers
inhibit the phosphorylation of ADP without affecting e- transport
(ex. 2,4-dinitrophenol)
Uncouplers are (hydrophobilc/philic) molecules with a ___ proton
hydrophobic
dissociable
Oxygen consumption is tied to ___ dissipation
gradient
