Question 1

Which of the following represents the correct order of electron flow in Complex I?

Accepted Answer

A)  NADH $\rightarrow$ ubiquinone $\rightarrow$ Fe-S clusters $\rightarrow$FMN 
B)  NADH $\rightarrow$Fe-S clusters $\rightarrow$ FMN $\rightarrow$ubiquinone 
C)  NADH $\rightarrow$ FMN $\rightarrow$ ubiquinone $\rightarrow$ Fe-S clusters 
D)  NADH $\rightarrow$ FMN $\rightarrow$Fe-S clusters $\rightarrow$ubiquinone 
E)  NADH $\rightarrow$ ubiquinone $\rightarrow$ FMN $\rightarrow$Fe-S clusters 
A)  NADH $\rightarrow$ ubiquinone $\rightarrow$ Fe-S clusters $\rightarrow$FMN 
B)  NADH $\rightarrow$Fe-S clusters $\rightarrow$ FMN $\rightarrow$ubiquinone 
C)  NADH $\rightarrow$ FMN $\rightarrow$ ubiquinone $\rightarrow$ Fe-S clusters 
D)  NADH $\rightarrow$ FMN $\rightarrow$Fe-S clusters $\rightarrow$ubiquinone 
E)  NADH $\rightarrow$ ubiquinone $\rightarrow$ FMN $\rightarrow$Fe-S clusters D

Question 2

If the pH of the matrix is 7.7, what is the pH of the intermembrane space if the $\Delta$G for transport of H+ is 20 kJ/mol at 37$\degree$C with $\Delta$$\Psi$ = 170 mV?

Accepted Answer

A)  2.6 
B)  7.1 
C)  8.3 
D)  12.8 
E)  cannot be determined 
A)  2.6 
B)  7.1 
C)  8.3 
D)  12.8 
E)  cannot be determined B

Question 3

How many cytochrome c molecules are oxidized by Complex IV for each molecule of oxygen that is reduced?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  It depends upon the efficiency of the electron transfer in Complex IV. 
A)  1 
B)  2 
C)  3 
D)  4 
E)  It depends upon the efficiency of the electron transfer in Complex IV. D

Question 4

Aconitase catalyzes the _____ of citrate, followed by a _____ reaction.

Accepted Answer

A)  oxidation; reduction 
B)  reduction; oxidation 
C)  hydration; dehydration 
D)  dehydration; hydration 
E)  isomerization; isomerization 
A)  oxidation; reduction 
B)  reduction; oxidation 
C)  hydration; dehydration 
D)  dehydration; hydration 
E)  isomerization; isomerization

Question 5

_____ and pyruvate can be combined in an ATP-dependent reaction that regenerates one of the key intermediates in the citric acid cycle.

Accepted Answer

The answer of _____ and pyruvate can be combined in...

Question 6

In the malate-aspartate shuttle, _____ is reduced to _____ in the cytosol.

Accepted Answer

A)  aspartate; oxaloacetate 
B)  oxaloacetate; malate 
C)  aspartate; malate 
D)  malate; aspartate 
E)  malate; oxaloacetate 
A)  aspartate; oxaloacetate 
B)  oxaloacetate; malate 
C)  aspartate; malate 
D)  malate; aspartate 
E)  malate; oxaloacetate

Question 7

Complex IV uses _____ and _____ ions to reduce oxygen to water.

Accepted Answer

A)  manganese; iron 
B)  copper; iron 
C)  manganese; copper 
D)  zinc; copper 
E)  iron; zinc 
A)  manganese; iron 
B)  copper; iron 
C)  manganese; copper 
D)  zinc; copper 
E)  iron; zinc

Question 8

The imbalance of protons across the inner mitochondrial membrane is referred to as _____.

Accepted Answer

A)  the protonmotive force 
B)  the chemiosmotic force 
C)  the electron transport force 
D)  the ATP synthase force 
E)  the proton gradient force 
A)  the protonmotive force 
B)  the chemiosmotic force 
C)  the electron transport force 
D)  the ATP synthase force 
E)  the proton gradient force

Question 9

For eukaryotes, where are the complexes of electron transport located?

Accepted Answer

A)  cytosol 
B)  outer mitochondrial membrane 
C)  mitochondrial intermembrane space 
D)  inner mitochondrial membrane 
E)  mitochondrial matrix 
A)  cytosol 
B)  outer mitochondrial membrane 
C)  mitochondrial intermembrane space 
D)  inner mitochondrial membrane 
E)  mitochondrial matrix

Question 10

______ catalyzes a substrate-level phosphorylation reaction within the citric acid cycle.

Accepted Answer

Succinyl-C

Question 11

The process of _____ allows electrons to be transferred between redox centers that are up to 1.4 nm apart.

Accepted Answer

A)  reduction 
B)  swinging arm electron transfer 
C)  electron shuttling 
D)  electron teleporting 
E)  tunneling 
A)  reduction 
B)  swinging arm electron transfer 
C)  electron shuttling 
D)  electron teleporting 
E)  tunneling

Question 12

In the citric acid cycle, what reduced cofactors are derived from the oxidation of one molecule of acetyl-CoA to two molecules of CO2?

Accepted Answer

A)  2 NADH and 1 FADH2 
B)  3 NADH and 1 FADH2 
C)  2 NADH and 2 FADH2 
D)  3 NADH and 2 FADH2 
E)  4 NADH and 2 FADH2 
A)  2 NADH and 1 FADH2 
B)  3 NADH and 1 FADH2 
C)  2 NADH and 2 FADH2 
D)  3 NADH and 2 FADH2 
E)  4 NADH and 2 FADH2

Question 13

The reaction catalyzed by fumarase is _____.

Accepted Answer

A)  an isomerization of an alcohol 
B)  a dehydration of an alcohol 
C)  a hydroxylation of an alkene 
D)  a hydration of an alkene 
E)  none of the above 
A)  an isomerization of an alcohol 
B)  a dehydration of an alcohol 
C)  a hydroxylation of an alkene 
D)  a hydration of an alkene 
E)  none of the above

Question 14

Which of the following is inhibited by high levels of acetyl-CoA?

Accepted Answer

A)  malate dehydrogenase 
B)  succinyl-CoA synthetase 
C)  pyruvate carboxylase 
D)  pyruvate dehydrogenase 
E)  $\alpha$-ketoglutarate dehydrogenase 
A)  malate dehydrogenase 
B)  succinyl-CoA synthetase 
C)  pyruvate carboxylase 
D)  pyruvate dehydrogenase 
E)  $\alpha$-ketoglutarate dehydrogenase

Question 15

Which of the following can be converted into glutamic acid in a single enzyme-catalyzed step?

Accepted Answer

A)  isocitrate 
B)  oxaloacetate 
C)  malate 
D) $\alpha$-ketoglutarate 
E)  succinyl-CoA 
A)  isocitrate 
B)  oxaloacetate 
C)  malate 
D) $\alpha$-ketoglutarate 
E)  succinyl-CoA

Question 16

Considering the reactions within the citric acid cycle, which of the following molecules will be produced from the intermediate pictured on the right?

Accepted Answer

A)  citrate 
B)  isocitrate 
C)  succinate 
D)  succinyl-CoA 
E)  $\alpha$-ketoglutarate 
A)  citrate 
B)  isocitrate 
C)  succinate 
D)  succinyl-CoA 
E)  $\alpha$-ketoglutarate

Question 17

Which of the following enzymes contains an FAD prosthetic group?

Accepted Answer

A)  pyruvate dehydrogenase 
B)  isocitrate dehydrogenase 
C)  succinate dehydrogenase 
D)  $\alpha$-ketoglutarate dehydrogenase 
E)  malate dehydrogenase 
A)  pyruvate dehydrogenase 
B)  isocitrate dehydrogenase 
C)  succinate dehydrogenase 
D)  $\alpha$-ketoglutarate dehydrogenase 
E)  malate dehydrogenase

Question 18

How does the reaction catalyzed by malate dehydrogenase proceed despite a $\Delta$G$\degree$' of 29.7 kJ/mol?

Accepted Answer

A)  An elevated [H+] allows the reaction to proceed. 
B)  High levels of NAD+ allow the reaction to proceed. 
C)  Concentrations of oxaloacetate are kept very low by rapid use in the subsequent step. 
D)  The enzyme is unique in its ability to catalyze the reaction in only one direction. 
E)  The enzyme catalyzed reaction under cellular conditions has a much smaller energy of activation. 
A)  An elevated [H+] allows the reaction to proceed. 
B)  High levels of NAD+ allow the reaction to proceed. 
C)  Concentrations of oxaloacetate are kept very low by rapid use in the subsequent step. 
D)  The enzyme is unique in its ability to catalyze the reaction in only one direction. 
E)  The enzyme catalyzed reaction under cellular conditions has a much smaller energy of activation.

Question 19

Given the following structure of isocitrate, the carbon labeled _____ is lost as CO2 by isocitrate dehydrogenase, and the carbon labeled _____ is lost as CO2 by $\alpha$-ketoglutarate dehydrogenase.

Accepted Answer

A)  1; 2 
B)  2; 1 
C)  1; 3 
D)  3; 1 
E)  2; 3 
A)  1; 2 
B)  2; 1 
C)  1; 3 
D)  3; 1 
E)  2; 3

Question 20

Which of the following enzymes catalyzes a substrate-level phosphorylation?

Accepted Answer

A)  malate synthase 
B)  succinate dehydrogenase 
C)  $\alpha$-ketoglutarate dehydrogenase 
D)  succinyl-CoA synthetase 
E)  fumarase 
A)  malate synthase 
B)  succinate dehydrogenase 
C)  $\alpha$-ketoglutarate dehydrogenase 
D)  succinyl-CoA synthetase 
E)  fumarase

Exam 7: The Common Catabolic Pathway

Which of the following represents the correct order of electron flow in Complex I?

If the pH of the matrix is 7.7, what is the pH of the intermembrane space if the Δ\DeltaΔ G for transport of H+ is 20 kJ/mol at 37 °\degree° C with Δ\DeltaΔΨ\PsiΨ = 170 mV?

How many cytochrome c molecules are oxidized by Complex IV for each molecule of oxygen that is reduced?

Aconitase catalyzes the _____ of citrate, followed by a _____ reaction.

_____ and pyruvate can be combined in an ATP-dependent reaction that regenerates one of the key intermediates in the citric acid cycle.

In the malate-aspartate shuttle, _____ is reduced to _____ in the cytosol.

Complex IV uses _____ and _____ ions to reduce oxygen to water.

The imbalance of protons across the inner mitochondrial membrane is referred to as _____.

For eukaryotes, where are the complexes of electron transport located?

______ catalyzes a substrate-level phosphorylation reaction within the citric acid cycle.

The process of _____ allows electrons to be transferred between redox centers that are up to 1.4 nm apart.

In the citric acid cycle, what reduced cofactors are derived from the oxidation of one molecule of acetyl-CoA to two molecules of CO2?

The reaction catalyzed by fumarase is _____.

Which of the following is inhibited by high levels of acetyl-CoA?

Which of the following can be converted into glutamic acid in a single enzyme-catalyzed step?

Considering the reactions within the citric acid cycle, which of the following molecules will be produced from the intermediate pictured on the right?

Which of the following enzymes contains an FAD prosthetic group?

How does the reaction catalyzed by malate dehydrogenase proceed despite a Δ\DeltaΔ G °\degree° ' of 29.7 kJ/mol?

Given the following structure of isocitrate, the carbon labeled _____ is lost as CO2 by isocitrate dehydrogenase, and the carbon labeled _____ is lost as CO2 by α\alphaα -ketoglutarate dehydrogenase.

Which of the following enzymes catalyzes a substrate-level phosphorylation?

The Chemical Foundations of Biochemistry

Nucleic Acids

Proteins I

Proteins Iienzymes

Membranes and an Introduction to Signal Transduction

Carbohydrates I

Carbohydrates II

Lipids I

Lipids II

Amine Metabolism

Metabolism Integration

Nucleotide Deoxynucleotide Metabolism

Dna Replication, Damage and Repair

Rna Synthesis

Protein

Control of Gene

Determination of Macromolecular Structure

Allosterism and Receptor-Ligand

Designer Proteins and Protein Folding

Biomolecule Purification

Bioinformatics and Omics

Signal

Protein Trafficking

Photosynthesis Nitrogen

Filters

If the pH of the matrix is 7.7, what is the pH of the intermembrane space if the $\Delta$ G for transport of H⁺ is 20 kJ/mol at 37 $\degree$ C with $\Delta$ $\Psi$ = 170 mV?

Aconitase catalyzes the _ of citrate, followed by a _ reaction.

In the malate-aspartate shuttle, _ is reduced to _ in the cytosol.

Complex IV uses _ and _ ions to reduce oxygen to water.

In the citric acid cycle, what reduced cofactors are derived from the oxidation of one molecule of acetyl-CoA to two molecules of CO₂?

How does the reaction catalyzed by malate dehydrogenase proceed despite a $\Delta$ G $\degree$ ' of 29.7 kJ/mol?