Question 1

Which of the following statements about mitochondrial transport systems is correct?

Accepted Answer

A)  malate-aspartate shuttle: converts cytosolic NADH to mitochondrial FADH2 
B)  ATP-ADP translocase: transfers ATP and a proton from matrix to cytosol while transferring ADP from cytosol to matrix 
C)  glycerophosphate shuttle: converts cytosolic FADH2 to mitochondrial NADH 
D)  the malate-aspartate shuttle is irreversible while the glycerophosphate shuttle is reversible 
E)  none of the above are correct 
A)  malate-aspartate shuttle: converts cytosolic NADH to mitochondrial FADH2 
B)  ATP-ADP translocase: transfers ATP and a proton from matrix to cytosol while transferring ADP from cytosol to matrix 
C)  glycerophosphate shuttle: converts cytosolic FADH2 to mitochondrial NADH 
D)  the malate-aspartate shuttle is irreversible while the glycerophosphate shuttle is reversible 
E)  none of the above are correct

Question 2

All of the following take place in the Q cycle EXCEPT:

Accepted Answer

A)  transfer of electrons from bL to bH. 
B)  an electron is passed from bL to UQ. 
C)  an electron is passed from bH to UQ. 
D)  one UQH2 is returned to the pool. 
E)  two protons are pumped into the matrix. 
A)  transfer of electrons from bL to bH. 
B)  an electron is passed from bL to UQ. 
C)  an electron is passed from bH to UQ. 
D)  one UQH2 is returned to the pool. 
E)  two protons are pumped into the matrix.

Question 3

A molecule such as 2,4-dinitrophenol works to uncouple the proton gradient. Which of the following is true about 2,4-DNP?

Accepted Answer

A)  2,4-DNP is protonated in the matrix and deprotonated in the intermembrane space. 
B)  The presence of an uncoupler results in an increase in the activity of the TCA cycle and electron transport 
C)  2,4-DNP is a very ineffective uncoupler because its hydrophobic structure prevents it from effectively crossing lipid bilayer membranes. 
D)  2,4-DNP has been used as a very effective diet aid for the past 70 years 
E)  none of the above are correct 
A)  2,4-DNP is protonated in the matrix and deprotonated in the intermembrane space. 
B)  The presence of an uncoupler results in an increase in the activity of the TCA cycle and electron transport 
C)  2,4-DNP is a very ineffective uncoupler because its hydrophobic structure prevents it from effectively crossing lipid bilayer membranes. 
D)  2,4-DNP has been used as a very effective diet aid for the past 70 years 
E)  none of the above are correct

Question 4

Another name for complex II (succinate dehydrogenase) in the electron transport chain is:

Accepted Answer

A)  cytochrome c oxidase. 
B)  NADH-CoQ reductase. 
C)  succinate-CoQ reductase. 
D)  cytochrome c reductase. 
E)  cytochrome bc1 complex. 
A)  cytochrome c oxidase. 
B)  NADH-CoQ reductase. 
C)  succinate-CoQ reductase. 
D)  cytochrome c reductase. 
E)  cytochrome bc1 complex.

Question 5

Explain the cycle of reactions that are part of the malate-aspartate shuttle.​

Accepted Answer

Oxaloacetate is reduced to malate in the

Question 6

The complete reduction of one molecule of oxygen gas requires how many electrons?

Accepted Answer

A)  two 
B)  three 
C)  four 
D)  eight 
E)  six 
A)  two 
B)  three 
C)  four 
D)  eight 
E)  six

Question 7

Discuss the binding change mechanism proposed by Boyer.​

Accepted Answer

Boyer proposed that the conformational c

Question 8

All of the following are in the mitochondria EXCEPT:

Accepted Answer

A)  enzymes for fatty acid oxidation. 
B)  adenylate kinase. 
C)  creatine kinase. 
D)  the electron transport complexes. 
E)  pentose phosphate pathway. 
A)  enzymes for fatty acid oxidation. 
B)  adenylate kinase. 
C)  creatine kinase. 
D)  the electron transport complexes. 
E)  pentose phosphate pathway.

Question 9

Characteristics of proton gradient driven enzyme conformational change in ATP synthase include all EXCEPT:

Accepted Answer

A)  binding of substrates. 
B)  ATP synthesis. 
C)  catalytic cooperativity between subunits. 
D)  conformational change in the β-subunits releasing ATP. 
E)  (αβ)3 complex rotates relative to a fixed β-subunit. 
A)  binding of substrates. 
B)  ATP synthesis. 
C)  catalytic cooperativity between subunits. 
D)  conformational change in the β-subunits releasing ATP. 
E)  (αβ)3 complex rotates relative to a fixed β-subunit.

Question 10

Which complex will be affected if rotenone is added?

Accepted Answer

A)  complex I 
B)  complex II 
C)  complex III 
D)  complex IV 
E)  none, it is an uncoupler 
A)  complex I 
B)  complex II 
C)  complex III 
D)  complex IV 
E)  none, it is an uncoupler

Question 11

P/O ratio is defined as:

Accepted Answer

A)  Pi uptake per oxygen atom by mitochondria. 
B)  molecules of phosphate released from ATP per oxygen utilized by muscle tissue. 
C)  ratio of atoms of phosphorous to oxygen in phosphate (Pi). 
D)  molecules of ATP formed per two electrons flowing through electron transport chain. 
E)  none of the above. 
A)  Pi uptake per oxygen atom by mitochondria. 
B)  molecules of phosphate released from ATP per oxygen utilized by muscle tissue. 
C)  ratio of atoms of phosphorous to oxygen in phosphate (Pi). 
D)  molecules of ATP formed per two electrons flowing through electron transport chain. 
E)  none of the above.

Question 12

All are characteristics of the malate-aspartate shuttle EXCEPT:

Accepted Answer

A)  OAA translocates inner mitochondrial membrane. 
B)  electrons of cytosolic NADH are translocated to mitochondrial NADH. 
C)  two malate dehydrogenase enzymes. 
D)  reactions are reversible. 
E)  all are true. 
A)  OAA translocates inner mitochondrial membrane. 
B)  electrons of cytosolic NADH are translocated to mitochondrial NADH. 
C)  two malate dehydrogenase enzymes. 
D)  reactions are reversible. 
E)  all are true.

Question 13

All are characteristics of the binding charge mechanism EXCEPT:

Accepted Answer

A)  one site is empty (O-sites). 
B)  one site contains ADP and Pi (L-sites). 
C)  T-sites become O-sites. 
D)  energy-driven conformational changes convert O-sites to L-sites. 
E)  T-sites bind ATP. 
A)  one site is empty (O-sites). 
B)  one site contains ADP and Pi (L-sites). 
C)  T-sites become O-sites. 
D)  energy-driven conformational changes convert O-sites to L-sites. 
E)  T-sites bind ATP.

Question 14

Which of the following correctly and completely describes electron movement in electron transport?

Accepted Answer

A)  NADH → complex I → complex III → coenzyme Q → Complex IV → O2 
B)  [FADH2] → complex II → cytochrome c → complex III → coenzyme Q → Complex IV → O2 
C)  NADH → complex I → coenzyme Q → complex III → cytochrome c → Complex IV → O2 
D)  [FADH2] → complex I → coenzyme Q →complex III → Complex IV → O2 
E)  none of the above 
A)  NADH → complex I → complex III → coenzyme Q → Complex IV → O2 
B)  [FADH2] → complex II → cytochrome c → complex III → coenzyme Q → Complex IV → O2 
C)  NADH → complex I → coenzyme Q → complex III → cytochrome c → Complex IV → O2 
D)  [FADH2] → complex I → coenzyme Q →complex III → Complex IV → O2 
E)  none of the above

Question 15

What is the result of the reaction catalyzed by Complex I in the electron-transport chain?​

Accepted Answer

Complex I transports protons from the mi

Question 16

Which of the following is true regarding proton movement in the mitochondria?

Accepted Answer

A)  complex III pumps 2 protons across the inner membrane 
B)  protons move from the matrix to the inner membrane space via the a and c subunits of ATP synthase to produce ATP 
C)  2,4-dinitrophenol moves protons from the inner membrane space to the matrix without ATP synthesis 
D)  the matrix becomes acidic due to the proton movement coupled to electron transport 
E)  none of the above 
A)  complex III pumps 2 protons across the inner membrane 
B)  protons move from the matrix to the inner membrane space via the a and c subunits of ATP synthase to produce ATP 
C)  2,4-dinitrophenol moves protons from the inner membrane space to the matrix without ATP synthesis 
D)  the matrix becomes acidic due to the proton movement coupled to electron transport 
E)  none of the above

Question 17

Which of the following is/are mobile electron carrier(s)?
A.UQ
B.Cyt c
C.Complex III

Accepted Answer

A)  A only 
B)  B only 
C)  C only 
D)  B & C 
E)  A & B 
A)  A only 
B)  B only 
C)  C only 
D)  B & C 
E)  A & B

Question 18

Spontaneity of a redox reaction depends upon each of the following EXCEPT:

Accepted Answer

A)  standard cell potential 
B)  concentration of the species being oxidized 
C)  concentration of the species being reduced 
D)  a and b only 
E)  a, b, and c 
A)  standard cell potential 
B)  concentration of the species being oxidized 
C)  concentration of the species being reduced 
D)  a and b only 
E)  a, b, and c

Question 19

____ creates a passive proton channel through which protons flow from the cytosol to the mitochondrial matrix in ____.

Accepted Answer

A)  Oligomycin; microorganisms 
B)  Thermogenin (UCP1); brown adipose tissue 
C)  Demerol; nerve tissue 
D)  Obesin; adipocytes 
E)  none of the above 
A)  Oligomycin; microorganisms 
B)  Thermogenin (UCP1); brown adipose tissue 
C)  Demerol; nerve tissue 
D)  Obesin; adipocytes 
E)  none of the above

Question 20

In ATP synthase, the ____ subunit is the site of ATP synthesis while the ____ subunit forms the proton channel through the inner mitochondrial membrane.

Accepted Answer

A)  α; a 
B)  β; α 
C)  β; c 
D)  γ; c 
E)  a; γ 
A)  α; a 
B)  β; α 
C)  β; c 
D)  γ; c 
E)  a; γ

Exam 20: Electron Transport and Oxidative Phosphorylation

Which of the following statements about mitochondrial transport systems is correct?

All of the following take place in the Q cycle EXCEPT:

A molecule such as 2,4-dinitrophenol works to uncouple the proton gradient. Which of the following is true about 2,4-DNP?

Another name for complex II (succinate dehydrogenase) in the electron transport chain is:

Explain the cycle of reactions that are part of the malate-aspartate shuttle.​

The complete reduction of one molecule of oxygen gas requires how many electrons?

Discuss the binding change mechanism proposed by Boyer.​

All of the following are in the mitochondria EXCEPT:

Characteristics of proton gradient driven enzyme conformational change in ATP synthase include all EXCEPT:

Which complex will be affected if rotenone is added?

P/O ratio is defined as:

All are characteristics of the malate-aspartate shuttle EXCEPT:

All are characteristics of the binding charge mechanism EXCEPT:

Which of the following correctly and completely describes electron movement in electron transport?

What is the result of the reaction catalyzed by Complex I in the electron-transport chain?​

Which of the following is true regarding proton movement in the mitochondria?

Which of the following is/are mobile electron carrier(s)? A.UQ B.Cyt c C.Complex III

Spontaneity of a redox reaction depends upon each of the following EXCEPT:

____ creates a passive proton channel through which protons flow from the cytosol to the mitochondrial matrix in ____.

In ATP synthase, the ____ subunit is the site of ATP synthesis while the ____ subunit forms the proton channel through the inner mitochondrial membrane.

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, Tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Membranes and Membrane Transport

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Enzymeskinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Metabolism: an Overview

Glycolysis

The Tricarboxylic Acid Cycle

Photosynthesis

Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Lipid Biosynthesis

Nitrogen Acquisition and Amino Acid Metabolism

Synthesis and Degradation of Nucleotides

Metabolic Integration and Organ Specialization

Dna Metabolism: Replication, Recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

Completing the Protein Life Cycle: Folding, Processing, and Degradation

The Reception and Transmission of Extracellular Information

Filters

Explain the cycle of reactions that are part of the malate-aspartate shuttle.

Discuss the binding change mechanism proposed by Boyer.

What is the result of the reaction catalyzed by Complex I in the electron-transport chain?

creates a passive proton channel through which protons flow from the cytosol to the mitochondrial matrix in .

In ATP synthase, the subunit is the site of ATP synthesis while the subunit forms the proton channel through the inner mitochondrial membrane.