Question 1

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

Accepted Answer

In the fully oxidized state, ubiquinone (Q), has two keto groups. The addition of electrons and protons generates ubiquinol (QH2), the fully reduced form. Therefore, electron transfer reactions are coupled to proton binding and release.

Question 2

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

Accepted Answer

Complex II is not a proton pump. When electrons flow from FADH₂to oxygen, as catalyzed by Complex II, Complex III, and Complex IV, fewer protons are pumped out of the matrix as compared to NADH. Thus, fewer ATP molecules are ultimately made.

Question 3

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

Accepted Answer

copper

Question 4

A strong oxidizing agent has a strong tendency to ________________ (accept, donate) electron(s).

Accepted Answer

The answer of A strong oxidizing agent has a strong...

Question 5

Another name for ubiquinone is ________________.

Accepted Answer

The answer of Another name for ubiquinone is ________________.
...

Question 6

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

Accepted Answer

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

Question 7

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

Accepted Answer

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

Question 8

Which of the following does not pump protons?

Accepted Answer

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

Question 9

Complex IV is also known as ________________.

Accepted Answer

Cytochrome

Question 10

Choose the correct answer from the list below. Not all of the answers will be used.
-_______________ is an ATP-generating process in which an inorganic substance such as oxygen serves as the ultimate electron acceptor.

Accepted Answer

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) 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

Question 11

Cytochrome ________________ is the only water-soluble cytochrome of the electron-transport chain.

Accepted Answer

The answer of Cytochrome ________________ is the only water-soluble cytochrome...

Question 12

What is a cytochrome?

Accepted Answer

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. 
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 13

Choose the correct answer from the list below. Not all of the answers will be used.
-The enzyme _______________ catalyzes the reduction of O2.

Accepted Answer

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) 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

Question 14

To what extent is ATP recycled on a daily basis?

Accepted Answer

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. 
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 15

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

Accepted Answer

The answer of ________________ is an enzyme that scavenges H2O2...

Question 16

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

Accepted Answer

Two enzymes, superoxide dismutase and ca

Question 17

The Q cycle:

Accepted Answer

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. 
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 18

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

Accepted Answer

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 
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 19

Choose the correct answer from the list below. Not all of the answers will be used.
-_______________ is the complex with three Fe-sulfhydryl electron acceptors.

Accepted Answer

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) 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

Question 20

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

Accepted Answer

Electrons are transferred from FMNH2 to

Exam 20: The Electron Transport Chain

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

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

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

A strong oxidizing agent has a strong tendency to ________________ (accept, donate) electron(s).

Another name for ubiquinone is ________________.

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

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

Which of the following does not pump protons?

Complex IV is also known as ________________.

Choose the correct answer from the list below. Not all of the answers will be used. -_______________ is an ATP-generating process in which an inorganic substance such as oxygen serves as the ultimate electron acceptor.

Cytochrome ________________ is the only water-soluble cytochrome of the electron-transport chain.

What is a cytochrome?

Choose the correct answer from the list below. Not all of the answers will be used. -The enzyme _______________ catalyzes the reduction of O2.

To what extent is ATP recycled on a daily basis?

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

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

The Q cycle:

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

Choose the correct answer from the list below. Not all of the answers will be used. -_______________ is the complex with three Fe-sulfhydryl electron acceptors.

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

Biochemistry and the Unity of Life

Water, Weak Bonds, and the Generation of Order Out of Chaos

Amino Acids

Protein Three-Dimensional Structure

Techniques in Protein Biochemistry

Basic Concepts of Enzyme Action

Kinetics and Regulation

Mechanisms and Inhibitors

Hemoglobin: an Allosteric Protein

Carbohydrates

Lipids

Membrane Structure and Function

Signal Transduction Pathways

Digestion: Turning a Meal Into Cellular Biochemicals

Metabolism: Basic Concepts and Design

Glycolysis

Gluconeogenesis

Preparation for the Cycle

Harvesting Electrons From the Cycle

The Proton-Motive Force

The Light Reactions

The Calvin Cycle

Glycogen Degradation

Glycogen Synthesis

The Pentose Phosphate Pathway

Fatty Acid Degredation

Fatty Acid Synthesis

Lipid Synthesis

Amino Acid Degradation and the Urea Cycle

Amino Acids Synthesis

Nucleotide Metabolism

The Structure of Informational Macromolecules: Dna and Rna

DNA Replication

DNA Repair and Recombination

RNA Synthesis and Regulation in Prokaryotes

Gene Expression in Eukaryotes

RNA Processing in Eukaryotes

The Genetic Code

The Mechanism of Protein Synthesis

Recombinant DNA Techniques

Filters

Choose the correct answer from the list below. Not all of the answers will be used. -The enzyme _______________ catalyzes the reduction of O₂.