Question 1

Which of the following is not a factor contributing to the large free energy of hydrolysis of ATP?

Accepted Answer

A)  Electrostatic repulsion of oxygen atoms 
B)  Better solvation of products than ATP itself 
C)  Complexes with Mg2+ or Mn2+ ions 
D)  Better stability of products than ATP itself 
E)  Electrical shielding of products of hydrolysis 
A)  Electrostatic repulsion of oxygen atoms 
B)  Better solvation of products than ATP itself 
C)  Complexes with Mg2+ or Mn2+ ions 
D)  Better stability of products than ATP itself 
E)  Electrical shielding of products of hydrolysis

Question 2

Fatty acid synthesis occurs in the , while fatty acid breakdown occurs in the .

Accepted Answer

A)  cytosol; mitochondria 
B)  cytosol; nucleus 
C)  mitochondria; cytosol 
D)  Golgi apparatus; cytosol 
A)  cytosol; mitochondria 
B)  cytosol; nucleus 
C)  mitochondria; cytosol 
D)  Golgi apparatus; cytosol

Question 3

Mutant organisms can be helpful in the study of metabolism because

Accepted Answer

A)  one can compare the mutant to a non-mutant organism. 
B)  there may be an indication of a natural role for an enzyme. 
C)  there may be accumulations of products prior to defective enzymes. 
D)  the structures of enzymes may be deduced. 
E)  All of the above 
A)  one can compare the mutant to a non-mutant organism. 
B)  there may be an indication of a natural role for an enzyme. 
C)  there may be accumulations of products prior to defective enzymes. 
D)  the structures of enzymes may be deduced. 
E)  All of the above

Question 4

Phosphatases catalyze the hydrolytic removal of phosphate groups.

Accepted Answer

A) True 
 B)False

Question 5

g-Glutamyl phosphate is formed as an intermediate in the conversion of glutamate to glutamine by the enzyme glutamine synthetase because

Accepted Answer

A)  it has a large negative free energy. 
B)  it is positively charged. 
C)  it is unstable in water. 
D)  it is a nucleophile. 
E)  All of the above 
A)  it has a large negative free energy. 
B)  it is positively charged. 
C)  it is unstable in water. 
D)  it is a nucleophile. 
E)  All of the above

Question 6

Phosphorylation at the expense of ATP is catalyzed by .

Accepted Answer

A)  protein kinases 
B)  phosphoryl isomerases 
C)  phosphatases 
D)  All of the above 
A)  protein kinases 
B)  phosphoryl isomerases 
C)  phosphatases 
D)  All of the above

Question 7

A reaction that best serves as a control point for regulation .

Accepted Answer

A)  is a near equilibrium reaction 
B)  has a large positive △G 
C)  is metabolically irreversible 
D)  follows Michaelis-Menten kinetics 
A)  is a near equilibrium reaction 
B)  has a large positive △G 
C)  is metabolically irreversible 
D)  follows Michaelis-Menten kinetics

Question 8

If the standard reduction potential of a certain half-reaction is -0.30 V, which statement below is true for this half-reaction to proceed as a reduction?

Accepted Answer

A)  This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential greater than +0.30 V. 
B)  This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential greater than -0.30 V. 
C)  This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential less than -0.30 V. 
D)  It doesnʹt matter what half-reaction this is coupled with, it will proceed spontaneously. 
A)  This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential greater than +0.30 V. 
B)  This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential greater than -0.30 V. 
C)  This half-reaction will proceed if it is coupled to another half-reaction that has a standard reduction potential less than -0.30 V. 
D)  It doesnʹt matter what half-reaction this is coupled with, it will proceed spontaneously.

Question 9

Nucleoside triphosphates exist in a cell as complexes with

Accepted Answer

A)  Phosphate ion. 
B)  Mg2+ only. 
C)  Mn2+ only. 
D)  Mg2+ and sometimes Mn2+. 
E)  All of the above 
A)  Phosphate ion. 
B)  Mg2+ only. 
C)  Mn2+ only. 
D)  Mg2+ and sometimes Mn2+. 
E)  All of the above

Question 10

Calculate △G°ʹ for the reaction shown if the mass action ratio, Q, is 5.3 × 102 M-1 and △G is 46 kJ/mol at a temperature of 298 K. R = 8.315 J/K-mol) ADP + Pi ⇌ ATP

Accepted Answer

A)  30 kJ/mol 
B)  -30 kJ/mol 
C)  61 kJ/mol 
D)  -61 kJ/mol 
A)  30 kJ/mol 
B)  -30 kJ/mol 
C)  61 kJ/mol 
D)  -61 kJ/mol

Question 11

In order for a reaction to proceed spontaneously from left to right as written

Accepted Answer

A)  ATP must be involved in the reaction. 
B)  a common intermediate must be formed. 
C)  the overall free-energy change must be negative. 
D)  a phosphate group must be transferred. 
E)  All of the above 
A)  ATP must be involved in the reaction. 
B)  a common intermediate must be formed. 
C)  the overall free-energy change must be negative. 
D)  a phosphate group must be transferred. 
E)  All of the above

Question 12

Phosphagens are energy-rich phosphoanhydrides found in animal muscle cells and which have higher group-transfer potentials than ATP.

Accepted Answer

A) True 
 B)False

Question 13

Ten people are sitting in a row. Their objective is to whisper a secret from one person to the next all the way down the row. The first person whispers the secret to the second person who passes the secret to the third person and so on. After whispering to the third person, the second person in the row notices the ninth person has fallen asleep in their chair, so she gets up, goes down the row and shakes person nine awake. This example is similar to .

Accepted Answer

A)  allosteric control 
B)  positive cooperativity 
C)  feed-forward activation 
D)  negative modulation 
A)  allosteric control 
B)  positive cooperativity 
C)  feed-forward activation 
D)  negative modulation

Question 14

Which thermodynamic quantity is used to determine if a reaction in a cell is spontaneous?

Accepted Answer

A)  △G°ʹ  
B)  △G 
C)  △H 
D)  △S 
A)  △G°ʹ  
B)  △G 
C)  △H 
D)  △S

Question 15

Which compound has a greater free energy of hydrolysis than ATP?

Accepted Answer

A)  glucose 1-phosphate 
B)  any phosphoester 
C)  phosphoenolpyruvate 
D)  acetyl CoA 
E)  All of the above 
A)  glucose 1-phosphate 
B)  any phosphoester 
C)  phosphoenolpyruvate 
D)  acetyl CoA 
E)  All of the above

Question 16

Calculate the equilibrium constant for an oxidation-reduction reaction involving the transfer of 1 mole of electrons with DE0ʹ= 0.25 V. R = 8.315 JK-1mol-1, F = 96.48 kJV-1mol-1, T = 298 K)

Accepted Answer

A)  1 
B)  6 x 10-5  
C)  1.7 x 104  
D)  0.49 
A)  1 
B)  6 x 10-5  
C)  1.7 x 104  
D)  0.49

Question 17

The chemical energy generated by oxidation reactions cannot be captured by

Accepted Answer

A)  NADH. 
B)  NADP. 
C)  FMN. 
D)  FAD. 
E)  Q. 
A)  NADH. 
B)  NADP. 
C)  FMN. 
D)  FAD. 
E)  Q.

Question 18

All metabolic reactions occur in the cytosol of cells.

Accepted Answer

A) True 
 B)False

Question 19

The glycolytic pathway oxidizes glucose to two molecules of pyruvate and also produces a net of two molecules of ATP. ATP allosterically inhibits the enzyme, PFK-1, that catalyzes the third step of glycolysis. This is an example of .

Accepted Answer

A)  feed-forward activation 
B)  feedback inhibition 
C)  negative cooperativity 
D)  competitive inhibition 
A)  feed-forward activation 
B)  feedback inhibition 
C)  negative cooperativity 
D)  competitive inhibition

Question 20

Which are membrane associated pathways?

Accepted Answer

A)  electron transport chain in eukaryotes 
B)  citric acid cycle in bacteria 
C)  photosynthesis 
D)  glycolysis 
E)  Both A and C above 
A)  electron transport chain in eukaryotes 
B)  citric acid cycle in bacteria 
C)  photosynthesis 
D)  glycolysis 
E)  Both A and C above

Exam 10: Introduction to Metabolism

Which of the following is not a factor contributing to the large free energy of hydrolysis of ATP?

Fatty acid synthesis occurs in the , while fatty acid breakdown occurs in the .

Mutant organisms can be helpful in the study of metabolism because

Phosphatases catalyze the hydrolytic removal of phosphate groups.

g-Glutamyl phosphate is formed as an intermediate in the conversion of glutamate to glutamine by the enzyme glutamine synthetase because

Phosphorylation at the expense of ATP is catalyzed by .

A reaction that best serves as a control point for regulation .

If the standard reduction potential of a certain half-reaction is -0.30 V, which statement below is true for this half-reaction to proceed as a reduction?

Nucleoside triphosphates exist in a cell as complexes with

Calculate △G°ʹ for the reaction shown if the mass action ratio, Q, is 5.3 × 102 M-1 and △G is 46 kJ/mol at a temperature of 298 K. R = 8.315 J/K-mol) ADP + Pi ⇌ ATP

In order for a reaction to proceed spontaneously from left to right as written

Phosphagens are energy-rich phosphoanhydrides found in animal muscle cells and which have higher group-transfer potentials than ATP.

Which thermodynamic quantity is used to determine if a reaction in a cell is spontaneous?

Which compound has a greater free energy of hydrolysis than ATP?

Calculate the equilibrium constant for an oxidation-reduction reaction involving the transfer of 1 mole of electrons with DE0ʹ= 0.25 V. R = 8.315 JK-1mol-1, F = 96.48 kJV-1mol-1, T = 298 K)

The chemical energy generated by oxidation reactions cannot be captured by

All metabolic reactions occur in the cytosol of cells.

The glycolytic pathway oxidizes glucose to two molecules of pyruvate and also produces a net of two molecules of ATP. ATP allosterically inhibits the enzyme, PFK-1, that catalyzes the third step of glycolysis. This is an example of .

Which are membrane associated pathways?

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

Filters

Calculate △G°^ʹfor the reaction shown if the mass action ratio, Q, is 5.3 × 10²M^-¹and △G is 46 kJ/mol at a temperature of 298 K. R = 8.315 J/K-mol) ADP + P_i⇌ ATP

Calculate the equilibrium constant for an oxidation-reduction reaction involving the transfer of 1 mole of electrons with DE^0ʹ= 0.25 V. R = 8.315 JK^-¹mol^-¹, F = 96.48 kJV^-¹mol^-¹, T = 298 K)