Deck 20: The Electron Transport Chain

Question 1

Complex IV is also known as ________________.

Answer 1

Cytochrome c oxidase

Question 2

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
A strong oxidizing agent has a strong tendency to ________________ (accept, donate) electron(s).

Answer 2

accept

Question 3

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
The electron carrier _______________ is a derivative of quinone and has an isoprenoid tail.

Answer 3

c

Question 4

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
_______________ is the complex with three Fe-sulfhydryl electron acceptors.

Question 5

________________ is an enzyme that scavenges H2O2 and converts it to molecular oxygen and water.

Question 6

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
_______________ is the prosthetic group in Complex I that accepts electrons from NADH.

Question 7

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
The permeability of the outer mitochondrial membrane is primarily due to the presence of _______________.

Question 8

________________ carries electrons from Complex III to Complex IV.

Question 9

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
Cytochrome ________________ is the only water-soluble cytochrome of the electron-transport chain.

Question 10

________________ donates electrons to cytochrome C.

Question 11

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
The enzyme _______________ catalyzes the reduction of O2.

Question 12

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
_______________ is where oxidative phosphorylation occurs in eukaryotes.

Question 13

The transfer of a single electron to O2 forms the reactive ________________ ion.

Question 14

________________ is/are the result of uncontrolled electron transfer to oxygen

Question 15

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
The prosthetic group _______________ is present in complexes I, II, and III of electron transport.

Question 16

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
_______________: The process by which cytoplasmic NADH can be oxidized by O2 using the electron-transport system.

Question 17

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
_______________ is an ATP-generating process in which an inorganic substance such as oxygen serves as the ultimate electron acceptor.

Question 18

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
Another name for ubiquinone is ________________.

Question 19

Cytochrome c oxidase contains two heme A groups and three ________________ ions.

Question 20

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) mitochondria
b) ubiquinone
c) coenzyme Q
d) flavin mononucleotide (FMN)
e) iron-sulfur clusters
f) respiration
g) transporters
h) porins
i) succinate dehydrogenase
j) cytochrome c oxidase
k) Complex II
l) Complex III
The citric acid cycle enzyme _______________ is also part of an electron-transport complex.

Question 21

Give the balanced equation for the net reaction catalyzed by Q-cytochrome c oxidoreducatase.

Question 22

The Q cycle:

A) transfers electrons from a two-electron carrier to a one-electron carrier.
B) recycles protons.
C) acts as an NADH exchange with the cytosol.
D) A and B.
E) A, B and C.

Question 23

Describe the path by which electrons from FADH2 enter the electron-transport chain.

Question 24

To what extent is ATP recycled on a daily basis?

A) 50 ATPs per day
B) 300 ATPs per day
C) 1500 ATPs per day
D) 3000 ATPs per day
E) None of the above.

Question 25

Explain why less ATP is made from the reoxidation of FADH2 compared to NADH.

Question 26

Calculate the ∆G°ʹ for the reaction where lactate + NAD+ is converted to pyruvate + NADH.

Question 27

Describe the role that Q takes as the NADH-Q oxidoreductase transfers electrons from NADH to coenzyme Q.

Question 28

Coenzyme Q is also called:

A) NADH.
B) oxidoreductase.
C) ubiquinone.
D) All of the above.
E) None of the above.

Question 29

What are the mechanisms that a cell uses to protect against the production of oxygen radicals?

Question 30

Choose the correct path taken by a pair of electrons as they travel down the electron-transport chain.

A) NADH → Complex I → CoQ → Complex III → Cytochrome c → Complex IV → O2
B) FADH2 → Complex I → CoQ → Complex III → Cytochrome c → Complex IV → O2
C) NADH → Complex I → Complex II→ Complex III → Cytochrome c → Complex IV → O2
D) FADH2 → Complex II → CoQ → Complex III → Cytochrome c → Complex IV → O2
E) A and D

Question 31

Electron flow down the electron-transport chain leads to:

A) the transport of protons across the inner mitochondrial membrane from inside the matrix to the intermembrane space.
B) the transport of protons across the inner mitochondrial membrane from the intermembrane space into the matrix.
C) the coupled synthesis of GTP.
D) a dangerous imbalance of K+ ions across the mitochondrial membrane.
E) None of the above.

Question 32

What is a cytochrome?

A) a protein that transfers electrons and that also contains a heme prosthetic group
B) a chloroplast protein that transfers electrons and that also contains an iron-sulfur prosthetic group
C) a protein that pumps ATP and that also contains iron
D) All of the above.
E) None of the above.

Question 33

In proteins, these amino acid residues usually complex to the iron-sulfur clusters.

A) glycine
B) arginine
C) cysteine
D) All of the above.
E) None of the above.

Question 34

What pathologic condition(s) results from free-radical injury?

A) emphysema
B) Parkinson's disease
C) diabetes
D) atherogenesis
E) All of the above.

Question 35

In the Rieske center, the iron-sulfur center is coordinated to the amino acid(s):

A) histidine
B) cysteine
C) histidine and cysteine
D) cysteine and methionine
E) None of the above.

Question 36

What is a major defense strategy against oxidative damage caused by reactive oxygen species (ROS)?

Question 37

Which of the following does not participate in, nor is a component of, the electron-transport chain?

A) coenzyme A
B) nonheme, iron-sulfur proteins
C) coenzyme Q
D) cytochrome c1
E) NADH

Question 38

Which of the following does not pump protons?

A) Complex I
B) Complex II
C) Complex III
D) Complex IV
E) All of the above.

Question 39

What is the "dead zone" in the Gulf of Mexico and how did it come into being?

Question 40

In a table of reduction potentials, values for E`0 are given as plus (+) or minus (-). What is this in reference to?

Question 41

What are the fully oxidized and fully reduced states of coenzyme Q and how are they related to transmembrane proton transport?

Question 42

In which direction do electrons flow in the electron transport chain?

Question 43

What are the two half-reactions for the reduction of O2 by NADH?