Oxidative Phosphorilation Flashcards
Oxidative phosphorilation contains
Several steps of exergonic electron transfer
It is the __________ source of cellular ATP
Major
Electron transport takes place in _____
Mitochondria
The _____ encloses the matrix and includes _____
Inner mitochondrial matrix, specific transport proteins
As electrons are being passed through _______, protons are pumped from the matrix into _______
The electron transport chain, intermembrane space
The generated _____ provides the energy for ATP synthesis
Proton concentration gradient
The ______ contain porins and therefore is permeable to most small molecules
Outer mitochondrial membrane
The _____ is impermeable to most molecules
Inner mitochondrial membrane
The inner membrane is ideal for maintaining ______
Concentration gradients
The human body contains ______ of mitochondrial inner membrane, similar to 3 football fields
14,000 m^2
ATP and ADP Transport in Mitochondria is ______
Tighly regulated
_________ protein imports ADP and exports _____
ATP Translocase, ATP
A _____ permits simultaneous movement of ___ and H+
Symport, Pi
Net ATP yield of ______ depends on how electrons from ________ are transported into the mitochondrial matrix
glucose catabolism, cytoplasmic NADH
The number of ____ transported by each complex is ____ , but it is widely accepted that ____ are transported per ____ molecule oxidized
Protons, unclear, 10 H+, NADH
There are _____ protein complexes associate with the _____
four, electron transport chain
_______ transfers electrons from ____ to Ubiquinone (Q)
Complex 1, NADH
The citric acid cycle, fatty acid oxidation, and other processes also generate _______ ubiquinol (QH2)
Mitochondrial
_______ is succinate dehydrogenase which produces ____
Complex 2, QH2
_____ transfers electrons from ubiquinol to reduce ____
Complex 3, cytochrome c
_______ transfers electrons from _____ to reduce O2 to _____
Complex 4, cytochrome c, H20
Reduction potential indicates how likely a molecule is to _____
Gain an electron
Electrons travel from molecules with the ____ , to molecules with the _____
Lowest reduction potential, highest
In the electron transport chain, ____ is the reduced molecule which is the ______
NADH, initial source of electrons
________: NADH-Ubiquinone Oxidoreductase
Complex 1
_______: Succinate-Ubiquinone Oxidoreductase
Complex 2
_____: Ubiquinol-Cytochrome C Oxidoreductase
Complex 3
_____ :Cytochrome C Oxidase
Complex 4
Complex 1 transfers electrons from____ to ______ (Q) to generate ______
NADH, Ubiquinone, Ubiquinol (QH2)
In complex 1, electrons transfer from _____ to _____, then from FMN to _____
NADH, FMN, Q
There are several co-factors required for electron transfer, including multiple ______
Iron-Sulfur Clusters (FeS)
______ is reduced to ubiquinol (QH2), which can diffuse through the membrane to ______
Ubiquinone, Complex 3
As electrons are transferred from _____ to ______, Complex 1 transfers _____ from the matrix to the intermembrane space
NADH, Ubiquinone, four protons
NADH initially transfers _______ to FMN, electrons are then transferred to a series of ______, ____ at a time
Two electrons, FeS clusters, one
Iron-sulfur clusters are coordinated with ____ thiols
Cys
Electrons from the FeS clusters are transferred ____at a time to _______
One, Ubiquinone (Q)
____ is fully reduced to ubiquinol (QH2) and diffuses through the membrane to _____
Ubiquinone, complex 3
______ reactions contribute to the ubiquinol pool
Oxidation-reduction
Succinate Dehydrogenase (______), produces ___ during the citric acid cycle
Complex 2, QH2
_________ (__), is also produced during fatty acid ________
Ubiquinol, QH2, oxidation
Electrons from ________ may enter the mitochondrial _____ pool through the _____ pathway
cytosolic NADH, ubiquinol, 3-phosphoglycerol
_____ transfers electrons from ubiquinol (QH2) to a series of _____ one electron at a time
Complex 3, cytochromes
____ are proteins with heme prosthetic groups
Cytochromes
Unlike the ____ groups in myoglobin and hemoglobin, the heme in _____ undergoes reversible _____ transfers
Heme, cytochrome c, one-electron
The central iron atom can be ___ (Fe3+) or ____ (Fe2+)
oxidized, reduced
In complex 3, ____ are transferred one at a time from ___ to _____
electrons, ubiquinol,cytochrome c
Reduced ____ transfers electrons to ______
Cytochrome c, complex 4
Transfer of two electrons from one molecule of ubiquinol to two molecules of _____ also pumps a total of _____ into the intermebrane space
Cytochrome c, four
The final recipient of electrons from ____ is cytochrome c which transfer one electron at a time to _____
Complex 3, Complex 4
Complex 4 ____ cytochrome c and ______ O2
oxidizes, reduces
______ (cytochrome oxidase), catalyzes the reduction of oxygen to form water
Complex 4
O2 is reduced to ___ through a series of FeS and copper (Cu) based _______ reactions in _____
H20, oxidation-reduction, complex 4
For every two electrons from cytochrome c, _____ are translocated into the intermembrane space
two protons
______ are transported per ubiquinol (QH2) molecule
6 protons
The _____ generated by the electron transport chain represents a source of ___ that can drive the formation of _____
proton gradient, free energy, ATP
The total free energy of the protonmotive force has a ______ and an ____ component
concentraiton, electrical
The protein that taps the electrochemical proton gradient to phosphorylate ___ is known as ______
ADP, ATP Synthase
ATP Synthase is also referred to as _____ of the ______
Complex 5, ETC
ATP Synthase is a ___ protein complex of _____
multisubunit, complexes
The ____ complex transports protons across the membrane along the ______
F0, proton gradient
The ___ complex is where _____ + ____ is converted to ATP
F1, ADP, Pi
______: F0F1 ATPase
ATP Synthase
_____ Synthase Rotates
ATP
A proton enters through the _____ subunit along its concentration gradient and binds to a ____
a, c subunit
The ___ subunit rotates away from the ____
c, a subunit
As a new ___ subunit reaches the a subunit a ___ is relased
c, proton
One rotation of the ring translocates 8 protons since there are 8 _____
c subunits
Proton transport down the gradient rotates the ___ subunit as the __ subunits turn
gamma, c
The ___ subunit changes the conformation of the ___ complex as it rotates
gamma, F1
The change in conformation of the _____ is couple to ATP synthesis
alpha-beta dimer
The alpha-beta subunits form ___ different conformations
Three
__ and ___ bind to the open conformation
ADP, Pi
____ is formed in the tight conformation
ATP
ATP is released in the ____ conformation
open
The ___ ratio describes the stoichiometry of oxidative phosphorylation
P:O
The P:O ratio is the number of _____ molecules produced per ____ atom ____
ATP, oxygen, reduced
The P:O ratios are based on the ____ movement of ATP ____ and linked to the number of ___ translocated per electron
mechanical, synthase, protons
The rate of ______ phosphorylation depends on the rate of _____
oxidative, fuel catabolism
Oxidative phosphorilation is regulated by the availability of ____ cofactors (____ and ____) produced by other metabolic processes
Reduced, NADH, QH2
_____ translocation drives the rotation of a portion of ATP _____
Proton, Synthase
_____-induced conformational changes allow ATP Synthase to bind ADP and Pi to phosphorylate ADP, and to relase ATP
Rotation
ATP () and ADP () are charge molecules, so they cannot freely diffuse across the mitochondrial membrane
-4,-3
Transport of ATP ___ the matrix is couple to transport of __ into the matrix
from, ADP
Pi uses the ____ gradient across the membrane created by ___ pumps of the ETC
H+, proton
ATP synthase ____ operate in the absence of ___
cannot, ADP
The proton gradient is ______ when ATP is abundant and ADP is scarce
not utilized
Electron flow along the ETC is inhibited when ATP is abundant and ADP is scarce, which leads to the accumulation of ____ and ____, which leads to the inhibition of the _____
NADH, FADH2, TCA Cycle
The inhibition of TCA cycle adds to inhibtion of ____
Glycolysis
Protonmotive force can also produce ____
heat
Body heat can be produced when protons run back along _____ without ______
the gradient, producing ATP
An alternative return route for the protons exists through an uncoupling protein in the inner membrane (_____)
Thermogenin
____ allows the return of protons to the matrix the protonmotive force ____ is released as _____
Thermogenin, energy, heat
Brown fat has high content of ___ molecules, (____), and higher number of ____ compared to normal cells
energy, fatty acids, mitochondria
_____ also have a higher than normal concentration of ____ in their inner membrane
Mitochondria, thermogenin
