Question 1

Each of the following regarding redox couples is true EXCEPT:

Accepted Answer

A)  standard reduction potentials are measured relative to a standard hydrogen cell (H+/H2) 
B)  for cells in which electrons flow toward the sample half-cell, the reduction potential is positive 
C)  a redox couple consists of a substance being oxidized, and the substance oxidizing it 
D)  a half-reaction involving the loss of electrons is an oxidation reaction 
E)  all are true statements. 
A)  standard reduction potentials are measured relative to a standard hydrogen cell (H+/H2) 
B)  for cells in which electrons flow toward the sample half-cell, the reduction potential is positive 
C)  a redox couple consists of a substance being oxidized, and the substance oxidizing it 
D)  a half-reaction involving the loss of electrons is an oxidation reaction 
E)  all are true statements. C

Question 2

What is the effect of first adding oligomycin and then 2,4-dinitrophenol to respiring mitochondria?

Accepted Answer

A)  First, electron transport and ATP synthesis speed up, then electron transport and ATP synthesis stops. 
B)  First, ATP synthesis and electron transport stop, then electron transport speeds up with no ATP synthesis. 
C)  First, electron transport speeds up while ATP synthesis stops, then electron transport and ATP synthesis stops. 
D)  First, electron transport stops while ATP synthesis continues, then electron transport and ATP synthesis stops. 
E)  Nothing, the uncoupler and inhibitor cancel each other out. 
A)  First, electron transport and ATP synthesis speed up, then electron transport and ATP synthesis stops. 
B)  First, ATP synthesis and electron transport stop, then electron transport speeds up with no ATP synthesis. 
C)  First, electron transport speeds up while ATP synthesis stops, then electron transport and ATP synthesis stops. 
D)  First, electron transport stops while ATP synthesis continues, then electron transport and ATP synthesis stops. 
E)  Nothing, the uncoupler and inhibitor cancel each other out. B

Question 3

What molecule is the electron donor to complex III?

Accepted Answer

A)  cytochrome c 
B)  UQH2 
C)  NADH 
D)  H2O 
E)  FADH2 
A)  cytochrome c 
B)  UQH2 
C)  NADH 
D)  H2O 
E)  FADH2 B

Question 4

All are properties of uncouplers EXCEPT:

Accepted Answer

A)  They dissipate the proton gradient. 
B)  ATP/ADP ratio increases. 
C)  Electron transport continues. 
D)  They were briefly used as weight-loss drugs. 
E)  Heat is produced. 
A)  They dissipate the proton gradient. 
B)  ATP/ADP ratio increases. 
C)  Electron transport continues. 
D)  They were briefly used as weight-loss drugs. 
E)  Heat is produced.

Question 5

Each of the following is a true statement EXCEPT:

Accepted Answer

A)  standard free energy change for a redox reaction is related to the standard cell potential 
B)  standard free energy change for a redox reaction is related to the number of electrons transferred 
C)  for redox reactions with negative standard cell potentials, standard free energy change is negative 
D)  redox reactions must occur in pairs, where the total number of electrons involved in the oxidation equals the total number involved in the reduction 
E)  all are true statements 
A)  standard free energy change for a redox reaction is related to the standard cell potential 
B)  standard free energy change for a redox reaction is related to the number of electrons transferred 
C)  for redox reactions with negative standard cell potentials, standard free energy change is negative 
D)  redox reactions must occur in pairs, where the total number of electrons involved in the oxidation equals the total number involved in the reduction 
E)  all are true statements

Question 6

All of the following transfer electrons to the UQ/UQH2 pool EXCEPT:

Accepted Answer

A)  fatty acyl-CoA dehydrogenase. 
B)  sn-glycerolphosphate dehydrogenase. 
C)  Complex I. 
D)  Complex II. 
E)  Complex IV. 
A)  fatty acyl-CoA dehydrogenase. 
B)  sn-glycerolphosphate dehydrogenase. 
C)  Complex I. 
D)  Complex II. 
E)  Complex IV.

Question 7

Discuss the P/O ratio of oxidative phosphorylation. What is the P/O ratio for the portion of the chain from succinate to O2?​

Accepted Answer

The P/O ratio is the number of molecules

Question 8

If an ATP synthase contains 12 c subunits, 3 α subunits and 3 β subunits, how many protons must pass through this complex for every ATP molecule synthesized and transported to the cytosol, assuming that each ATP synthesized requires one proton for transport to the cytosol.

Accepted Answer

A)  3 
B)  4 
C)  5 
D)  12 
E)  13 
A)  3 
B)  4 
C)  5 
D)  12 
E)  13

Question 9

Complex III takes up ____ proton(s) on the matrix side of the ____ membrane and releases ____ protons on the intermembrane side for each pair of ____ passed through the Q cycle.

Accepted Answer

A)  two; inner; four; electrons 
B)  one; inner; two; protons 
C)  two; inner; four; protons 
D)  one; outer; two; electrons 
E)  none are true 
A)  two; inner; four; electrons 
B)  one; inner; two; protons 
C)  two; inner; four; protons 
D)  one; outer; two; electrons 
E)  none are true

Question 10

All are characteristics of cyt c EXCEPT:

Accepted Answer

A)  accepts electrons from cyt c1. 
B)  water soluble. 
C)  globular with planar heme group near the center of the protein. 
D)  heme iron coordinated with histidine nitrogen and methionine sulfur atoms. 
E)  all are true. 
A)  accepts electrons from cyt c1. 
B)  water soluble. 
C)  globular with planar heme group near the center of the protein. 
D)  heme iron coordinated with histidine nitrogen and methionine sulfur atoms. 
E)  all are true.

Question 11

The model of electron transport includes all EXCEPT:

Accepted Answer

A)  mobile coenzyme Q collecting electrons. 
B)  four independent mobile complexes. 
C)  cyt c moving in the intermembrane space. 
D)  protons driven into the matrix. 
E)  proton gradient generated to produce ATP. 
A)  mobile coenzyme Q collecting electrons. 
B)  four independent mobile complexes. 
C)  cyt c moving in the intermembrane space. 
D)  protons driven into the matrix. 
E)  proton gradient generated to produce ATP.

Question 12

Cyanide and azide bind tightly to the ferric form of ____, and carbon monoxide toxicity arises from its affinity for the iron of ____.

Accepted Answer

A)  cyt c; cyt a3 
B)  cyt a3; hemoglobin 
C)  hemoglobin; hemoglobin 
D)  myoglobin; hemoglobin 
E)  cyt a; cyt a3 
A)  cyt c; cyt a3 
B)  cyt a3; hemoglobin 
C)  hemoglobin; hemoglobin 
D)  myoglobin; hemoglobin 
E)  cyt a; cyt a3

Question 13

All of the following are part of apoptosis EXCEPT:

Accepted Answer

A)  cytochrome c is released. 
B)  caspases are activated. 
C)  a series of proteolytic reactions. 
D)  the mitochondrial outer membrane protein-permeable pores close. 
E)  mitochondrial membrane permeabilization (MMP). 
A)  cytochrome c is released. 
B)  caspases are activated. 
C)  a series of proteolytic reactions. 
D)  the mitochondrial outer membrane protein-permeable pores close. 
E)  mitochondrial membrane permeabilization (MMP).

Question 14

The hypothesis for proton driven ATP synthesis depends on proton neutralization of the negative charge on c-subunit ____ residues as the rotor turns. This causes the ____-subunit to turn relative to the three ____-subunits.

Accepted Answer

A)  Ser; c; γ 
B)  Ser; b; β 
C)  Asp; β; γ 
D)  Arg; c; γ 
E)  Asp; γ; β 
A)  Ser; c; γ 
B)  Ser; b; β 
C)  Asp; β; γ 
D)  Arg; c; γ 
E)  Asp; γ; β

Question 15

All are flavoproteins EXCEPT:

Accepted Answer

A)  NADH-CoQ reductase (complex I). 
B)  succinate dehydrogenase (complex II). 
C)  coenzyme Q-cytochrome c oxidoreductase (complex III). 
D)  sn-glycerolphosphate dehydrogenase. 
E)  fatty acyl-CoA dehydrogenase-transferring protein. 
A)  NADH-CoQ reductase (complex I). 
B)  succinate dehydrogenase (complex II). 
C)  coenzyme Q-cytochrome c oxidoreductase (complex III). 
D)  sn-glycerolphosphate dehydrogenase. 
E)  fatty acyl-CoA dehydrogenase-transferring protein.

Question 16

Where does the energy that drives ATP synthesis come from?

Accepted Answer

A)  The proton gradient. 
B)  NAD+ and FAD. 
C)  The electron gradient. 
D)  The oxidation states of the complexes. 
E)  Molecular oxygen. 
A)  The proton gradient. 
B)  NAD+ and FAD. 
C)  The electron gradient. 
D)  The oxidation states of the complexes. 
E)  Molecular oxygen.

Question 17

The reaction, dihydroxyacetone phosphate (DHAP) + NADH → NAD+ + glycerol-3-phosphate, is catalyzed by:

Accepted Answer

A)  triose phosphate isomerase. 
B)  glycerol kinase. 
C)  DHAP dehydrogenase. 
D)  glycerol-3-phosphate dehydrogenase. 
E)  glycerol-3-phosphate reductase. 
A)  triose phosphate isomerase. 
B)  glycerol kinase. 
C)  DHAP dehydrogenase. 
D)  glycerol-3-phosphate dehydrogenase. 
E)  glycerol-3-phosphate reductase.

Question 18

A characteristic of the glycerophosphate shuttle is:

Accepted Answer

A)  It shuttles NADH across the mitochondrial membrane to yield 2.5 ATP/ADH. 
B)  It shuttles "NADH electron equivalents" across the mitochondrial membrane to yield 1.5 ATP/NADH. 
C)  It only operates efficiently when the [NADH] in the cytoplasm is higher than in the matrix. 
D)  Malate is a key component in the shuttle process. 
E)  Aspartate is a key component in the shuttle process. 
A)  It shuttles NADH across the mitochondrial membrane to yield 2.5 ATP/ADH. 
B)  It shuttles "NADH electron equivalents" across the mitochondrial membrane to yield 1.5 ATP/NADH. 
C)  It only operates efficiently when the [NADH] in the cytoplasm is higher than in the matrix. 
D)  Malate is a key component in the shuttle process. 
E)  Aspartate is a key component in the shuttle process.

Question 19

What percentage of the proton gradient energy to synthesize and transport ATP to the cytosol is involved in the ATP-ADP transport?

Accepted Answer

A)  10% 
B)  15% 
C)  25% 
D)  50% 
E)  none of the above 
A)  10% 
B)  15% 
C)  25% 
D)  50% 
E)  none of the above

Question 20

Compounds with a large ____ reduction potential have a strong tendency to undergo oxidation, and as such, NADH is a strong ____ agent.

Accepted Answer

A)  positive; oxidizing 
B)  negative; reducing 
C)  negative; oxidizing 
D)  positive; reducing 
E)  can't be determined from information given 
A)  positive; oxidizing 
B)  negative; reducing 
C)  negative; oxidizing 
D)  positive; reducing 
E)  can't be determined from information given

Exam 20: Electron Transport and Oxidative Phosphorylation

Each of the following regarding redox couples is true EXCEPT:

What is the effect of first adding oligomycin and then 2,4-dinitrophenol to respiring mitochondria?

What molecule is the electron donor to complex III?

All are properties of uncouplers EXCEPT:

Each of the following is a true statement EXCEPT:

All of the following transfer electrons to the UQ/UQH2 pool EXCEPT:

Discuss the P/O ratio of oxidative phosphorylation. What is the P/O ratio for the portion of the chain from succinate to O2?​

If an ATP synthase contains 12 c subunits, 3 α subunits and 3 β subunits, how many protons must pass through this complex for every ATP molecule synthesized and transported to the cytosol, assuming that each ATP synthesized requires one proton for transport to the cytosol.

Complex III takes up ____ proton(s) on the matrix side of the ____ membrane and releases ____ protons on the intermembrane side for each pair of ____ passed through the Q cycle.

All are characteristics of cyt c EXCEPT:

The model of electron transport includes all EXCEPT:

Cyanide and azide bind tightly to the ferric form of ____, and carbon monoxide toxicity arises from its affinity for the iron of ____.

All of the following are part of apoptosis EXCEPT:

The hypothesis for proton driven ATP synthesis depends on proton neutralization of the negative charge on c-subunit ____ residues as the rotor turns. This causes the ____-subunit to turn relative to the three ____-subunits.

All are flavoproteins EXCEPT:

Where does the energy that drives ATP synthesis come from?

The reaction, dihydroxyacetone phosphate (DHAP) + NADH → NAD+ + glycerol-3-phosphate, is catalyzed by:

A characteristic of the glycerophosphate shuttle is:

What percentage of the proton gradient energy to synthesize and transport ATP to the cytosol is involved in the ATP-ADP transport?

Compounds with a large ____ reduction potential have a strong tendency to undergo oxidation, and as such, NADH is a strong ____ agent.

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

All of the following transfer electrons to the UQ/UQH₂ pool EXCEPT:

Discuss the P/O ratio of oxidative phosphorylation. What is the P/O ratio for the portion of the chain from succinate to O₂?

Complex III takes up proton(s) on the matrix side of the membrane and releases protons on the intermembrane side for each pair of passed through the Q cycle.

Cyanide and azide bind tightly to the ferric form of , and carbon monoxide toxicity arises from its affinity for the iron of .

The hypothesis for proton driven ATP synthesis depends on proton neutralization of the negative charge on c-subunit residues as the rotor turns. This causes the -subunit to turn relative to the three -subunits.

The reaction, dihydroxyacetone phosphate (DHAP) + NADH → NAD⁺ + glycerol-3-phosphate, is catalyzed by:

Compounds with a large reduction potential have a strong tendency to undergo oxidation, and as such, NADH is a strong agent.