Question 1

Which of the following would be considered a closed system?

Accepted Answer

A) a human living alone on a small island 
B) the planet Earth 
C) a fish living in a fish bowl 
D) a bacteria living in the large intestine 
E) a bacteria living in a Petri dish 
A) a human living alone on a small island 
B) the planet Earth 
C) a fish living in a fish bowl 
D) a bacteria living in the large intestine 
E) a bacteria living in a Petri dish B

Question 2

The highly exergonic nature of ATP hydrolysis is explained by which of the following?

Accepted Answer

A) the resulting orthophosphate is stabilized by resonance 
B) electrostatic repulsion occurs between phosphate groups and the adenine base of ATP 
C) the resulting product undergoes tautomerization to the keto form of ADP 
D) the bond that is hydrolyzed is considered an ester of phosphoric acid,making it highly unstable 
E) all of the above 
A) the resulting orthophosphate is stabilized by resonance 
B) electrostatic repulsion occurs between phosphate groups and the adenine base of ATP 
C) the resulting product undergoes tautomerization to the keto form of ADP 
D) the bond that is hydrolyzed is considered an ester of phosphoric acid,making it highly unstable 
E) all of the above A

Question 3

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- $\to$ isocitrate (ES1U1P1$\circ$S1S1P0' = - 0.38 V)

Accepted Answer

A) ubiquinol $\to$ ubiquinone + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = - 0.04 V) 
B) FADH2 $\to$ FAD + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.22 V) 
C) NADH $\to$ NAD+ + H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.32 V) 
D) H2 $\to$ 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.42 V) 
E) pyruvate + CoA $\to$ acetyl CoA + CO2 + H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.48 V) 
A) ubiquinol $\to$ ubiquinone + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = - 0.04 V) 
B) FADH2 $\to$ FAD + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.22 V) 
C) NADH $\to$ NAD+ + H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.32 V) 
D) H2 $\to$ 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.42 V) 
E) pyruvate + CoA $\to$ acetyl CoA + CO2 + H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.48 V) E

Question 4

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

Question 5

Calculate the $\Delta$GS1U1P1$\circ$S1S1P0' for the oxidation of succinate to fumarate,a step in the citric acid cycle.
FAD + 2H+ + 2e- $\to$ FADH2 ES1U1P1$\circ$S1S1P0' = - 0.22 V
fumarate + 2H+ + 2e- $\to$ succinate ES1U1P1$\circ$S1S1P0' = + 0.03 V

Accepted Answer

ES1U1P1$\circ$S1S1P0' = - 0.25 V
@#LAT-DLM&GS1U1P1$\circ$S1S1P0' = -

Question 6

If acetyl phosphate is made from the combination of ATP and acetate,what is the $\Delta$GS1U1P1$\circ$S1S1P0'? How would this reaction proceed within a typical cell?

acetyl phosphate + H2O $\to$ acetate + Pi + H+ $\Delta$GS1U1P1$\circ$S1S1P0'= -43.1 kJ/mol
ATP + H2O $\to$ ADP + Pi + H+ $\Delta$GS1U1P1$\circ$S1S1P0' = -30.5 kJ/mol

Accepted Answer

@#LAT-DLM&GS1U1P1$\circ$S1S1P0' = +12.6 kJ/mol.If this reaction were

Question 7

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 8

Which of the following represents an apparent violation of the second law of thermodynamics?

Accepted Answer

A) the organization of free amino acids into a protein 
B) the tendency for dead cells to break down to smaller molecules 
C) the hydrolysis of nucleic acids into nucleotides 
D) the conversion of the polymer cellulose into glucose 
E) the tendency for a professor's desk to become cluttered 
A) the organization of free amino acids into a protein 
B) the tendency for dead cells to break down to smaller molecules 
C) the hydrolysis of nucleic acids into nucleotides 
D) the conversion of the polymer cellulose into glucose 
E) the tendency for a professor's desk to become cluttered

Question 9

The conversion of glucose-6-phosphate to fructose-6-phosphate has a $\Delta$G°´ of +1.7 kJ/mol but within a typical cell,the $\Delta$G is -2.9 kJ/mol.What can be said about the value of Keq and Q?

Accepted Answer

A) under standard conditions,Keq > 1;in the cell,Q eq 1 C) under standard conditions,Keq > 1;in the cell,Q > 1 D) under standard conditions,Keq < 1;in the cell,Q < 1 E) none of the above A) under standard conditions,Keq > 1;in the cell,Q eq 1 C) under standard conditions,Keq > 1;in the cell,Q > 1 D) under standard conditions,Keq < 1;in the cell,Q < 1 E) none of the above

Question 10

The typical concentration of glucose-6-phosphate (G6P)in a cell is 1 mM.What concentration of glucose-1-phosphate (G1P)would be required to make the interconversion of G6P and G1P freely reversible at 37 S1U1P1$\circ$S1S1P0C?

G1P + H2O $\to$ glucose + Pi $\Delta$GS1U1P1$\circ$S1S1P0' = -20.9 kJ/mol
G6P + H2O $\to$ glucose + Pi $\Delta$GS1U1P1$\circ$S1S1P0' = -13.8 kJ/mol

Accepted Answer

G1P @#LAT-DLM& G6P @#LAT-DLM&GS1U1P1$\circ$S1S1P0' = -7.1 kJ/mol
@#LAT-DLM&GS1U1P1$\circ$S1S1P0' = -RT ln Q

Question 11

What is the ES1U1P1$\circ$S1S1P0' for the spontaneous reaction that would result if the following reactions were coupled? 
NAD+ + H+ + 2e- $\to$ NADH ES1U1P1$\circ$S1S1P0' = -0.32 V
Pyruvate + 2H+ + 2e- $\to$ lactate ES1U1P1$\circ$S1S1P0' = -0.19 V

Accepted Answer

A) -0.51 V 
B) -0.13 V 
C) +0.13 V 
D) +0.51 V 
E) none of the above 
A) -0.51 V 
B) -0.13 V 
C) +0.13 V 
D) +0.51 V 
E) none of the above

Question 12

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 13

The formation of glucose-1-phosphate from glucose and orthophosphate has a $\Delta$GS1U1P1$\circ$S1S1P0' of + 20.9 kJ/mol.If this reaction were coupled to another reaction in order to produce an exergonic reaction,which of the following would produce an overall endergonic reaction and therefore not be suitable for coupling?

Accepted Answer

A) creatine phosphate + H2O $\to$ creatine + Pi 
B) AMP + H2O $\to$ adenosine + Pi 
C) ATP + H2O $\to$ AMP + PPi 
D) ATP + H2O $\to$ ADP + Pi 
E) 1,3-bisphosphoglycerate + H2O $\to$ 3-phosphoglycerate + Pi 
A) creatine phosphate + H2O $\to$ creatine + Pi 
B) AMP + H2O $\to$ adenosine + Pi 
C) ATP + H2O $\to$ AMP + PPi 
D) ATP + H2O $\to$ ADP + Pi 
E) 1,3-bisphosphoglycerate + H2O $\to$ 3-phosphoglycerate + Pi

Question 14

Which of the following best describes the relationship between the oxidation of glucose in a cell versus the oxidation of glucose in a bomb calorimeter?

Accepted Answer

A) both the reactions involved and the net enthalpy values are identical 
B) both the reactions involved and the net enthalpy values are different 
C) the reactions involved are identical but the net enthalpy values are different 
D) the reactions involved are different but the net enthalpy values are identical 
E) none of the above 
A) both the reactions involved and the net enthalpy values are identical 
B) both the reactions involved and the net enthalpy values are different 
C) the reactions involved are identical but the net enthalpy values are different 
D) the reactions involved are different but the net enthalpy values are identical 
E) none of the above

Question 15

Which of the following compounds contains a phosphate ester as its most energetically labile bond?

Accepted Answer

A) pyrophosphate 
B) adenosine monophosphate 
C) creatine phosphate 
D) 1,3-bisphosphoglycerate 
E) acetyl phosphate 
A) pyrophosphate 
B) adenosine monophosphate 
C) creatine phosphate 
D) 1,3-bisphosphoglycerate 
E) acetyl phosphate

Question 16

Based on the half reactions given below,which of the following reactants is the strongest reducing agent?

Accepted Answer

A) NADH $\to$ NAD+ + H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.32 V) 
B) dihydrolipoic acid $\to$ lipoic acid + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.29 V) 
C) FADH2 $\to$ FAD + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.22 V) 
D) lactate $\to$ pyruvate + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.18 V) 
E) succinate $\to$ fumarate + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = - 0.03 V) 
A) NADH $\to$ NAD+ + H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.32 V) 
B) dihydrolipoic acid $\to$ lipoic acid + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.29 V) 
C) FADH2 $\to$ FAD + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.22 V) 
D) lactate $\to$ pyruvate + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = + 0.18 V) 
E) succinate $\to$ fumarate + 2H+ + 2e- (ES1U1P1$\circ$S1S1P0' = - 0.03 V)

Question 17

Which of the following correctly relates the relative entropies?

Accepted Answer

A) sodium chloride crystals > sodium chloride dissolved in water 
B) carbon dioxide in air > dry ice 
C) carbon in a molecule of glucose > carbon in carbon dioxide gas 
D) a solution of ATP > the same solution with ATP converted to ADP and Pi 
E) ice made from pure water > ice made from salt water 
A) sodium chloride crystals > sodium chloride dissolved in water 
B) carbon dioxide in air > dry ice 
C) carbon in a molecule of glucose > carbon in carbon dioxide gas 
D) a solution of ATP > the same solution with ATP converted to ADP and Pi 
E) ice made from pure water > ice made from salt water

Question 18

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 $\to$ 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 $\to$ pyruvate + ATP 
E) all of the above

Question 19

If the $\Delta$GS1U1P1$\circ$S1S1P0'for ATP hydrolysis is -31 kJ/mol and the $\Delta$GS1U1P1$\circ$S1S1P0' for phosphoenolpyruvate hydrolysis is -62 kJ/mol,what is the $\Delta$GS1U1P1$\circ$S1S1P0' for the phosphorylation of ADP by phosphoenolpyruvate?

Accepted Answer

A) -93 kJ/mol 
B) -31 kJ/mol 
C) +31 kJ/mol 
D) +93 kJ/mol 
E) none of the above 
A) -93 kJ/mol 
B) -31 kJ/mol 
C) +31 kJ/mol 
D) +93 kJ/mol 
E) none of the above

Question 20

Which of the following best describes biochemical systems with respect to the first law of thermodynamics?

Accepted Answer

A) most biochemical systems operate at constant volume 
B) most biochemical systems operate at constant temperature 
C) most biochemical systems operate at constant pressure 
D) most biochemical systems operate with a constant number of molecules 
E) none of the above 
A) most biochemical systems operate at constant volume 
B) most biochemical systems operate at constant temperature 
C) most biochemical systems operate at constant pressure 
D) most biochemical systems operate with a constant number of molecules 
E) none of the above

Exam 3: The Energetics of Life

Which of the following would be considered a closed system?

The highly exergonic nature of ATP hydrolysis is explained by which of the following?

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- →\to→ isocitrate (E ∘\circ∘ ' = - 0.38 V)

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?

Calculate the Δ\DeltaΔ G ∘\circ∘ ' for the oxidation of succinate to fumarate,a step in the citric acid cycle. FAD + 2H+ + 2e- →\to→ FADH2 E ∘\circ∘ ' = - 0.22 V fumarate + 2H+ + 2e- →\to→ succinate E ∘\circ∘ ' = + 0.03 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 represents an apparent violation of the second law of thermodynamics?

The conversion of glucose-6-phosphate to fructose-6-phosphate has a Δ\DeltaΔ G°´ of +1.7 kJ/mol but within a typical cell,the Δ\DeltaΔ G is -2.9 kJ/mol.What can be said about the value of Keq and Q?

What is the E ∘\circ∘ ' for the spontaneous reaction that would result if the following reactions were coupled? NAD+ + H+ + 2e- →\to→ NADH E ∘\circ∘ ' = -0.32 V Pyruvate + 2H+ + 2e- →\to→ lactate E ∘\circ∘ ' = -0.19 V

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

Which of the following best describes the relationship between the oxidation of glucose in a cell versus the oxidation of glucose in a bomb calorimeter?

Which of the following compounds contains a phosphate ester as its most energetically labile bond?

Based on the half reactions given below,which of the following reactants is the strongest reducing agent?

Which of the following correctly relates the relative entropies?

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

If the Δ\DeltaΔ G ∘\circ∘ 'for ATP hydrolysis is -31 kJ/mol and the Δ\DeltaΔ G ∘\circ∘ ' for phosphoenolpyruvate hydrolysis is -62 kJ/mol,what is the Δ\DeltaΔ G ∘\circ∘ ' for the phosphorylation of ADP by phosphoenolpyruvate?

Which of the following best describes biochemical systems with respect to the first law of thermodynamics?

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^- $\to$ isocitrate (E^$\circ$' = - 0.38 V)

Calculate the $\Delta$ G^$\circ$' for the oxidation of succinate to fumarate,a step in the citric acid cycle. FAD + 2H⁺ + 2e^- $\to$ FADH₂ E^$\circ$' = - 0.22 V fumarate + 2H⁺ + 2e^- $\to$ succinate E^$\circ$' = + 0.03 V

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

The conversion of glucose-6-phosphate to fructose-6-phosphate has a $\Delta$ G°´ of +1.7 kJ/mol but within a typical cell,the $\Delta$ G is -2.9 kJ/mol.What can be said about the value of K_eq and Q?

What is the E^$\circ$' for the spontaneous reaction that would result if the following reactions were coupled? NAD⁺ + H⁺ + 2e^- $\to$ NADH E^$\circ$' = -0.32 V Pyruvate + 2H⁺ + 2e^- $\to$ lactate E^$\circ$' = -0.19 V

If the $\Delta$ G^$\circ$'for ATP hydrolysis is -31 kJ/mol and the $\Delta$ G^$\circ$' for phosphoenolpyruvate hydrolysis is -62 kJ/mol,what is the $\Delta$ G^$\circ$' for the phosphorylation of ADP by phosphoenolpyruvate?