Question 1

When a mixture of glucose 6-phosphate and fructose 6-phosphate is incubated with the enzyme phosphohexose isomerase (which catalyzes the interconversion of these two compounds) until equilibrium is reached,the final mixture contains twice as much glucose 6-phosphate as fructose 6-phosphate.Which one of the following statements is best applied to this reaction outlined below? (R = 8.315 J/mol·K;T = 298 K) 
Glucose 6-phosphate  →\rightarrow→  fructose 6-phosphate

Accepted Answer

A)  ( Δ\DeltaΔ G'° is incalculably large and negative.) 
B)  ( Δ\DeltaΔ G'° is -1.72 kJ/mol.) 
C)  ( Δ\DeltaΔ G'° is zero.) 
D)  ( Δ\DeltaΔ G'° is +1.72 kJ/mol.) 
E)  ( Δ\DeltaΔ G'° is incalculably large and positive.)  F) All of the above
G) D) and E)

Question 2

If the  Δ\DeltaΔ G'° of the reaction A →\rightarrow→  B is -40 kJ/mol,under standard conditions the reaction:

Accepted Answer

A)  is at equilibrium.
B)  will never reach equilibrium.
C)  will not occur spontaneously.
D)  will proceed at a rapid rate.
E)  will proceed spontaneously from A to B. F) B) and E)
G) A) and E)

Question 3

Muscle contraction involves the conversion of:

Accepted Answer

A)  chemical energy to kinetic energy.
B)  chemical energy to potential energy.
C)  kinetic energy to chemical energy.
D)  potential energy to chemical energy.
E)  potential energy to kinetic energy.F) A) and D)
G) B) and E)

Question 4

For the reaction A  →\rightarrow→   B,the Keq' is 104.If a reaction mixture originally contains 1 mmol of A and no B,which one of the following must be true?

Accepted Answer

A)  At equilibrium,there will be far more B than A.
B)  The rate of the reaction is very slow.
C)  The reaction requires coupling to an exergonic reaction in order to proceed.
D)  The reaction will proceed toward B at a very high rate.
E)  ( Δ\DeltaΔ  G'° for the reaction will be large and positive.)  F) A) and B)
G) B) and D)

Question 5

The hydrolysis of ATP has a large negative Δ\DeltaΔ  G'°;nevertheless it is stable in solution due to:

Accepted Answer

A)  entropy stabilization.
B)  ionization of the phosphates.
C)  resonance stabilization.
D)  the hydrolysis reaction being endergonic.
E)  the hydrolysis reaction having a large activation energy. F) A) and C)
G) B) and E)

Question 6

For the reaction A  →\rightarrow→   B,the Keq' is 10-6.If a reaction mixture originally contains 1 mmol of A and 1 mmol of B,which one of the following must be true?

Accepted Answer

A)  At equilibrium,there will be still be equal levels of A and B.
B)  The rate of the reaction is very slow.
C)  At equilibrium,the amount of A will greatly exceed the amount of B.
D)  The reaction will proceed toward B at a very high rate.
E)  ( Δ\DeltaΔ G'° for the reaction will be large and positive.)  F) C) and E)
G) A) and B)

Question 7

Explain what is meant by the statement: "Standard free-energy changes are additive." Give an example of the usefulness of this additive property in understanding how cells carry out thermodynamically unfavorable chemical reactions.

Accepted Answer

When two chemical reactions can be summe...

Question 8

Biological oxidation-reduction reactions always involve:

Accepted Answer

A)  direct participation of oxygen.
B)  formation of water.
C)  mitochondria.
D)  transfer of electron(s) .
E)  transfer of hydrogens.F) A) and B)
G) B) and E)

Question 9

Explain the relationships among the change in the degree of order,the change in entropy,and the change in free energy that occur during a chemical reaction.

Accepted Answer

Entropy is a measure of disorder.Thus,if...

Question 10

Which of the following is not nucleophilic?

Accepted Answer

A)  A proton
B)  A carbanion
C)  An imidazole
D)  A hydroxide
E)  A carboxylic acidF) A) and B)
G) A) and C)

Question 11

The standard free-energy changes for the reactions below are given.
Phosphocreatine  →\rightarrow→   creatine + Pi  Δ\DeltaΔ G'° = -43.0 kJ/mol
ATP  →\rightarrow→   ADP + Pi  Δ\DeltaΔ G'° = -30.5 kJ/mol
What is the overall Δ\DeltaΔ G'° for the following reaction?
Phosphocreatine + ADP  →\rightarrow→   creatine + ATP

Accepted Answer

A)  -73.5 kJ/mol
B)  -12.5 kJ/mol
C)  +12.5 kJ/mol
D)  +73.5 kJ/mol
E)  ( Δ\DeltaΔ G'° cannot be calculated without Keq'.)  F) A) and D)
G) A) and C)

Question 12

The reaction A + B  →\rightarrow→    C has a Δ\DeltaΔ G'° of -20 kJ/mol at 25° C.Starting under standard conditions,one can predict that:

Accepted Answer

A)  at equilibrium,the concentration of B will exceed the concentration of A.
B)  at equilibrium,the concentration of C will be less than the concentration of A.
C)  at equilibrium,the concentration of C will be much greater than the concentration of A or B.
D)  C will rapidly break down to A + B.
E)  when A and B are mixed,the reaction will proceed rapidly toward formation of C. F) B) and E)
G) C) and D)

Question 13

All of the following contribute to the large,negative,free-energy change upon hydrolysis of "high-energy" compounds except:

Accepted Answer

A)  electrostatic repulsion in the reactant.
B)  low activation energy of forward reaction.
C)  stabilization of products by extra resonance forms.
D)  stabilization of products by ionization.
E)  stabilization of products by solvation.F) A) and D)
G) All of the above

Exam 13: Principles of Bioenergetics

Which of the following is not nucleophilic?

Correct Answer
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All of the following contribute to the large,negative,free-energy change upon hydrolysis of "high-energy" compounds except:

Correct Answer
verified

Muscle contraction involves the conversion of:

Correct Answer
verified

Explain what is meant by the statement: "Standard free-energy changes are additive." Give an example of the usefulness of this additive property in understanding how cells carry out thermodynamically unfavorable chemical reactions.

Correct Answer
verified
When two chemical reactions can be summe...
View Answer

Biological oxidation-reduction reactions always involve:

Correct Answer
verified

If the $\Delta$ G'° of the reaction A $\rightarrow$ B is -40 kJ/mol,under standard conditions the reaction:

Correct Answer
verified

For the reaction A $\rightarrow$ B,the K_eq' is 10^-6.If a reaction mixture originally contains 1 mmol of A and 1 mmol of B,which one of the following must be true?

Correct Answer
verified

The hydrolysis of ATP has a large negative $\Delta$ G'°;nevertheless it is stable in solution due to:

Correct Answer
verified

Correct Answer
verified

For the reaction A $\rightarrow$ B,the K_eq' is 10⁴.If a reaction mixture originally contains 1 mmol of A and no B,which one of the following must be true?

Correct Answer
verified

The reaction A + B $\rightarrow$ C has a $\Delta$ G'° of -20 kJ/mol at 25° C.Starting under standard conditions,one can predict that:

Correct Answer
verified

Explain the relationships among the change in the degree of order,the change in entropy,and the change in free energy that occur during a chemical reaction.

Correct Answer
verified
Entropy is a measure of disorder.Thus,if...
View Answer

Correct Answer
verified

Exam 13: Principles of Bioenergetics

Which of the following is not nucleophilic?

Correct AnswerverifiedShow Answer

All of the following contribute to the large,negative,free-energy change upon hydrolysis of "high-energy" compounds except:

Correct AnswerverifiedShow Answer

Muscle contraction involves the conversion of:

Correct AnswerverifiedShow Answer

Explain what is meant by the statement: "Standard free-energy changes are additive." Give an example of the usefulness of this additive property in understanding how cells carry out thermodynamically unfavorable chemical reactions.

Correct AnswerverifiedWhen two chemical reactions can be summe...View AnswerShow Answer

Biological oxidation-reduction reactions always involve:

Correct AnswerverifiedShow Answer

If the Δ\DeltaΔ G'° of the reaction A →\rightarrow→ B is -40 kJ/mol,under standard conditions the reaction:

Correct AnswerverifiedShow Answer

For the reaction A →\rightarrow→ B,the Keq' is 10-6.If a reaction mixture originally contains 1 mmol of A and 1 mmol of B,which one of the following must be true?

Correct AnswerverifiedShow Answer

The hydrolysis of ATP has a large negative Δ\DeltaΔ G'°;nevertheless it is stable in solution due to:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

For the reaction A →\rightarrow→ B,the Keq' is 104.If a reaction mixture originally contains 1 mmol of A and no B,which one of the following must be true?

Correct AnswerverifiedShow Answer

The reaction A + B →\rightarrow→ C has a Δ\DeltaΔ G'° of -20 kJ/mol at 25° C.Starting under standard conditions,one can predict that:

Correct AnswerverifiedShow Answer

Explain the relationships among the change in the degree of order,the change in entropy,and the change in free energy that occur during a chemical reaction.

Correct AnswerverifiedEntropy is a measure of disorder.Thus,if...View AnswerShow Answer

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
When two chemical reactions can be summe...
View Answer

Correct Answer
verified

If the $\Delta$ G'° of the reaction A $\rightarrow$ B is -40 kJ/mol,under standard conditions the reaction:

Correct Answer
verified

For the reaction A $\rightarrow$ B,the K_eq' is 10^-6.If a reaction mixture originally contains 1 mmol of A and 1 mmol of B,which one of the following must be true?

Correct Answer
verified

The hydrolysis of ATP has a large negative $\Delta$ G'°;nevertheless it is stable in solution due to:

Correct Answer
verified

Correct Answer
verified

For the reaction A $\rightarrow$ B,the K_eq' is 10⁴.If a reaction mixture originally contains 1 mmol of A and no B,which one of the following must be true?

Correct Answer
verified

The reaction A + B $\rightarrow$ C has a $\Delta$ G'° of -20 kJ/mol at 25° C.Starting under standard conditions,one can predict that:

Correct Answer
verified

Correct Answer
verified
Entropy is a measure of disorder.Thus,if...
View Answer

Correct Answer
verified