29 Questions
What is the purpose of the electron transfer in the process described?
To drive the expulsion of four protons per pair of electrons from the matrix
What is the role of Complex II (Succinate Dehydrogenase) in this process?
It accepts two electrons from succinate and passes them via iron-sulfur centers to ubiquinone
What is the role of Complex III (Ubiquinone:Cytochrome C Oxidoreductase) in this process?
It reduces two molecules of cytochrome c using two electrons from QH2
What is the role of Cytochrome C in this process?
It is a soluble heme-containing protein in the Inter Membrane Space that carries a single electron from Complex III to Complex IV
How many electrons are carried by Cytochrome C in this process?
One electron
What is the net result of the electron transfer process described?
All of the above
What is the primary function of the cristae in mitochondria?
To increase the surface area for the electron transport chain and ATP synthase
Which of the following statements about the chemiosmotic mechanism in mitochondria is correct?
Electrons move through the respiratory chain due to the high reduction potential of oxygen and low reduction potentials of substrates
Where are the enzymes involved in the citric acid cycle located within the mitochondrion?
In the matrix
What is the primary driving force for ATP synthesis in mitochondria?
The proton gradient across the inner mitochondrial membrane
Which of the following statements about the mitochondrial matrix is correct?
It contains the enzymes involved in the citric acid cycle
What is the overall free-energy change (ΔG'o) for the transfer of electrons from NADH to O2?
-220 kJ/mol of NADH
What is the overall change in the redox potential (ΔE'o) for the transfer of electrons from NADH to O2?
1.14 V
How many protons are pumped out of the matrix into the intermembrane space for each electron pair transferred from NADH to O2?
10
What is the redox potential (E'o) for the O2/H2O redox pair?
0.816 V
What is the redox potential (E'o) for the NAD+/NADH redox pair?
-0.320 V
What is the free-energy change (ΔG'o) for the transfer of electrons from succinate to O2?
-151.5 kJ/mol of succinate
What is the result of two electrons reducing one half oxygen molecule?
One water molecule
How many protons are picked up from the matrix per four electrons in the process of reducing oxygen to water?
Four protons
What is the role of Complex IV (cytochrome oxidase) in the electron flow and proton movements in the respiratory chain?
Transfers two electrons from reduced cytochrome c to half O2
What is the total number of protons that flow from the matrix to the intermembrane space when a pair of electrons flow through Complexes I, III, and IV?
10 protons
Which electron carriers pass two electrons to Complex III in the electron transport chain?
QH2 and cytochrome c
How many protons are transferred to the intermembrane space when Complex IV transfers two electrons from reduced cytochrome c to half O2?
Four protons
Which of the following statements about electron carriers in the electron transport chain (ETC) is correct?
Ubiquinone can act as a junction between one-electron and two-electron donors/acceptors.
What is the primary function of the electron transport chain (ETC) protein complexes?
To pump protons out of the mitochondrial matrix, creating an electrochemical gradient.
Which of the following statements about the redox centers in the ETC protein complexes is incorrect?
Iron-sulfur clusters can only accept one electron at a time.
What is the role of ubiquinone (coenzyme Q) in the electron transport chain?
To shuttle electrons between one-electron and two-electron donors/acceptors.
Which of the following statements about the reduction of ubiquinone is correct?
It requires two electrons and two protons, occurring in two steps via a semiquinone radical intermediate.
What is the primary driving force for ATP synthesis in mitochondria?
The electrochemical potential created by the pumping of protons out of the matrix.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
