Question 1

Which of the following reactions would be a non-spontaneous process?

Accepted Answer

A) complete oxidation of glucose to carbon dioxide and water 
B) formation of phosphoenolpyruvate from pyruvate and Pi 
C) hydrolysis of ATP to ADP and Pi 
D) the coupled reaction of phosphoenolpyruvate + ADP $\rarr$ pyruvate + ATP 
E) all of the above 
A) complete oxidation of glucose to carbon dioxide and water 
B) formation of phosphoenolpyruvate from pyruvate and Pi 
C) hydrolysis of ATP to ADP and Pi 
D) the coupled reaction of phosphoenolpyruvate + ADP $\rarr$ pyruvate + ATP 
E) all of the above

Question 2

Which of the following reactions, if coupled to the reduction of $\alpha$-ketoglutarate, would give the most exergonic overall reaction? $\alpha$-ketoglutarate + CO2 + 2H+ + 2e- $\rarr$ isocitrate (E$\circ$' = - 0.38 V)

Accepted Answer

A) ubiquinol $\rarr$ ubiquinone + 2H+ + 2e- (E$\circ$'  = - 0.04 V) 
B) FADH2 $\rarr$ FAD + 2H+ + 2e- (E$\circ$'  = + 0.22 V) 
C) NADH $\rarr$ NAD+ + H+ + 2e- (E$\circ$'  = + 0.32 V) 
D) H2 $\rarr$2H+ + 2e- (E$\circ$'  = + 0.42 V) 
E) pyruvate + CoA $\rarr$ acetyl CoA + CO2 + H+ + 2e- (E$\circ$'  = + 0.48 V) 
A) ubiquinol $\rarr$ ubiquinone + 2H+ + 2e- (E$\circ$'  = - 0.04 V) 
B) FADH2 $\rarr$ FAD + 2H+ + 2e- (E$\circ$'  = + 0.22 V) 
C) NADH $\rarr$ NAD+ + H+ + 2e- (E$\circ$'  = + 0.32 V) 
D) H2 $\rarr$2H+ + 2e- (E$\circ$'  = + 0.42 V) 
E) pyruvate + CoA $\rarr$ acetyl CoA + CO2 + H+ + 2e- (E$\circ$'  = + 0.48 V)

Question 3

If the $\Delta$G value for a given biochemical reaction is a relatively large, positive value, which of the following is true?

Accepted Answer

A) the reaction is said to be exergonic 
B) the reaction is thermodynamically favorable 
C) the reverse reaction is thermodynamically favorable 
D) the reaction is freely reversible 
E) the reaction is at equilibrium 
A) the reaction is said to be exergonic 
B) the reaction is thermodynamically favorable 
C) the reverse reaction is thermodynamically favorable 
D) the reaction is freely reversible 
E) the reaction is at equilibrium

Question 4

Which of the following is a result of living cells not being at equilibrium?

Accepted Answer

A) the $\Delta$G for all reactions will always be negative 
B) all reactions proceed in only one direction 
C) if the concentration of products is greater than the concentration of reactants, the reaction will always proceed in the reverse direction 
D) the entropy of cells is always increasing 
E) the direction in which most reactions will proceed depends upon concentrations of reactants and products 
A) the $\Delta$G for all reactions will always be negative 
B) all reactions proceed in only one direction 
C) if the concentration of products is greater than the concentration of reactants, the reaction will always proceed in the reverse direction 
D) the entropy of cells is always increasing 
E) the direction in which most reactions will proceed depends upon concentrations of reactants and products

Question 5

If the change in entropy for a process is much less than the change in enthalpy, why might the entropy change be the dominant factor in determining the overall free energy of the process?

Accepted Answer

A) biochemical reactions are performed at relatively constant pressure 
B) biochemical reactions generally occur around 300 K. 
C) biochemical reactions involve few reactants and products 
D) biochemical reactions involve mixtures of molecules, never pure substances 
E) all of the above 
A) biochemical reactions are performed at relatively constant pressure 
B) biochemical reactions generally occur around 300 K. 
C) biochemical reactions involve few reactants and products 
D) biochemical reactions involve mixtures of molecules, never pure substances 
E) all of the above

Which of the following reactions would be a non-spontaneous process?

Which of the following reactions, if coupled to the reduction of $\alpha$ -ketoglutarate, would give the most exergonic overall reaction? $\alpha$ -ketoglutarate + CO₂ + 2H⁺ + 2e^- $\rarr$ isocitrate (E^$\circ$' = - 0.38 V)

If the $\Delta$ G value for a given biochemical reaction is a relatively large, positive value, which of the following is true?

Which of the following is a result of living cells not being at equilibrium?

If the change in entropy for a process is much less than the change in enthalpy, why might the entropy change be the dominant factor in determining the overall free energy of the process?

The Scope of Biochemistry

The Matrix of Life: Weak Interactions in an Aqueous Environment

Nucleic Acids

Introduction to Proteins: the Primary Level of Protein Structure

The Three-Dimensional Structure of Proteins

Protein Function and Evolution

Contractile Proteins and Molecular Motors

Carbohydrates: Sugars, Saccharides, Glycans

Lipids, Membranes and Cellular Transport

Enzymes: Biological Catalysts

Chemical Logic of Metabolism

Carbohydrate Metabolism: Glycolysis, Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Citric Acid Cycle and Glyoxylate Cycle

Electron Transport, Oxidative Phosphorylation, and Oxygen Metabolism

Photosynthesis

Lipid Metabolism I: Fatty Acids, Triacylglycerols, and Lipoproteins

Interorgan and Intracellular Coordination of Energy Metabolism in Vertebrates

Lipid Metabolism Ii: Membrane Lipids, Steroids, Isoprenoids, and Eicosanoids

Metabolism of Nitrogenous Compounds I: Principles of Biosynthesis, Utilization, and Turnover

Metabolism of Nitogenous Compounds II: Amino Acids, Porphyrins, and Neurotransmitters

Nucleotide Metabolism

Mechanisms of Signal Transduction

Genes, Genomes and Chromosomes

DNA Replication

DNA Restructuring: Repair, Recombination, Rearrangement, Amplification

Information Readout: Transcription and Post-Transcriptional Processing

Information Decoding: Translation and Post-Translational Protein Processing

Regulation of Gene Expression

Filters

Exam 3: The Energetics of Life

Which of the following reactions would be a non-spontaneous process?

Which of the following reactions, if coupled to the reduction of α\alphaα -ketoglutarate, would give the most exergonic overall reaction? α\alphaα -ketoglutarate + CO2 + 2H+ + 2e- →\rarr→ isocitrate (E ∘\circ∘ ' = - 0.38 V)

If the Δ\DeltaΔ G value for a given biochemical reaction is a relatively large, positive value, which of the following is true?

Which of the following is a result of living cells not being at equilibrium?

If the change in entropy for a process is much less than the change in enthalpy, why might the entropy change be the dominant factor in determining the overall free energy of the process?

The Scope of Biochemistry

The Matrix of Life: Weak Interactions in an Aqueous Environment

Nucleic Acids

Introduction to Proteins: the Primary Level of Protein Structure

The Three-Dimensional Structure of Proteins

Protein Function and Evolution

Contractile Proteins and Molecular Motors

Carbohydrates: Sugars, Saccharides, Glycans

Lipids, Membranes and Cellular Transport

Enzymes: Biological Catalysts

Chemical Logic of Metabolism

Carbohydrate Metabolism: Glycolysis, Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Citric Acid Cycle and Glyoxylate Cycle

Electron Transport, Oxidative Phosphorylation, and Oxygen Metabolism

Photosynthesis

Lipid Metabolism I: Fatty Acids, Triacylglycerols, and Lipoproteins

Interorgan and Intracellular Coordination of Energy Metabolism in Vertebrates

Lipid Metabolism Ii: Membrane Lipids, Steroids, Isoprenoids, and Eicosanoids

Metabolism of Nitrogenous Compounds I: Principles of Biosynthesis, Utilization, and Turnover

Metabolism of Nitogenous Compounds II: Amino Acids, Porphyrins, and Neurotransmitters

Nucleotide Metabolism

Mechanisms of Signal Transduction

Genes, Genomes and Chromosomes

DNA Replication

DNA Restructuring: Repair, Recombination, Rearrangement, Amplification

Information Readout: Transcription and Post-Transcriptional Processing

Information Decoding: Translation and Post-Translational Protein Processing

Regulation of Gene Expression

Filters

Which of the following reactions, if coupled to the reduction of $\alpha$ -ketoglutarate, would give the most exergonic overall reaction? $\alpha$ -ketoglutarate + CO₂ + 2H⁺ + 2e^- $\rarr$ isocitrate (E^$\circ$' = - 0.38 V)

If the $\Delta$ G value for a given biochemical reaction is a relatively large, positive value, which of the following is true?