Biochemistry 4th Edition by Christopher K. Mathews Test bank

<< Biological Psychology 12th Edition by James W. Kalat test bank Biochemistry 6th Edition by Jeremy M. Berg John L. Tymoczko Lubert Stryer Test Bank >>
Product Code: 222
Availability: In Stock
Price: $24.99
Qty:     - OR -   Add to Wish List
Add to Compare

Biochemistry 4th Edition by Christopher K. Mathews Test bank

Description

Multiple Choice Questions

1) In the study of thermodynamics, which of the following could be examined as a system?

A) an isolated mitochondria
B) a single muscle cell
C) an entire organism
D) the entire planet Earth
E) all of the above

Answer: E

Difficulty: 1 Topic: Energy, Heat and Work

2) Which of the following would be considered a closed system?

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

Answer: B

Difficulty: 1 Topic: Energy, Heat and Work

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

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

Answer: C

Difficulty: 1 Topic: Energy, Heat and Work

4) 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?

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

Answer: D

Difficulty: 2 Topic: Energy, Heat and Work

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

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 pyruvate + ATP
E) all of the above

Answer: B

Difficulty: 2 Topic: Entropy and the Second Law of Thermodynamics

6) Which of the following correctly relates the relative entropies?

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

Answer: B

Difficulty: 1 Topic: Entropy and the Second Law of Thermodynamics

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

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 professors desk to become cluttered

Answer: A

Difficulty: 1 Topic: Entropy and the Second Law of Thermodynamics

8) 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?

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

Answer: B

Difficulty: 2 Topic: Free Energy: The Second Law in Open Systems

9) If the G value for a given biochemical reaction is a relatively large, positive value, which of the following is true?

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

Answer: C

Difficulty: 2 Topic: Free Energy: The Second Law in Open Systems

10) Which of the following is true regarding a spontaneous reaction?

A) H must always be negative
B) the sign of S does not matter since the entropy value is relatively small
C) if both H and S are positive, TS must be larger than H
D) if both H and S are negative, the reaction will only proceed at high temperature
E) the only scenario that always produces a spontaneous reaction, regardless of temperature, is when H is positive and S is negative

Answer: C

Difficulty: 2 Topic: Free Energy: The Second Law in Open Systems

11) Which of the following conditions will produce a non-spontaneous reaction?

A) positive H, positive S, low temperature
B) negative H, positive S, high temperature
C) negative H, negative S, low temperature
D) negative H, positive S, high temperature
E) positive H, positive S, high temperature

Answer: A

Difficulty: 2 Topic: Free Energy: The Second Law in Open Systems

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

A) under standard conditions, Keq > 1; in the cell, Q < 1 B) under standard conditions, Keq < 1; in the cell, Q > 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 Answer: B Difficulty: 2 Topic: Free Energy and Chemical Reactions: Chemical Equilibrium 13) Which of the following is a result of living cells not being at equilibrium? A) the 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 Answer: E Difficulty: 2 Topic: Free Energy and Chemical Reactions: Chemical Equilibrium 14) Which of the following compounds contains a phosphate ester as its most energetically labile bond? A) pyrophosphate B) adenosine monophosphate C) creatine phosphate D) 1,3-bisphosphoglycerate E) acetyl phosphate Answer: B Difficulty: 2 Topic: High Energy Phosphate Compounds: Free Energy Sources in Biological Systems 15) The highly exergonic nature of ATP hydrolysis is explained by which of the following? 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 Answer: A Difficulty: 2 Topic: High Energy Phosphate Compounds: Free Energy Sources in Biological Systems 16) The biochemical standard state differs from standard state conditions in what way? A) pH = 7.0 B) T = 298.15 K C) activity of water = 0 D) ionic strength = 1 E) all of the above Answer: A Difficulty: 1 Topic: High Energy Phosphate Compounds: Free Energy Sources in Biological Systems 17) If the G for ATP hydrolysis is 31 kJ/mol and the G for phosphoenolpyruvate hydrolysis is 62 kJ/mol, what is the G for the phosphorylation of ADP by phosphoenolpyruvate? A) 93 kJ/mol B) 31 kJ/mol C) +31 kJ/mol D) +93 kJ/mol E) none of the above Answer: B Difficulty: 2 Topic: High Energy Phosphate Compounds: Free Energy Sources in Biological Systems 18) The formation of glucose-1-phosphate from glucose and orthophosphate has a G 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? A) creatine phosphate + H2O creatine + Pi B) AMP + H2O adenosine + Pi C) ATP + H2O AMP + PPi D) ATP + H2O ADP + Pi E) 1,3-bisphosphoglycerate + H2O 3-phosphoglycerate + Pi Answer: B Difficulty: 2 Topic: High Energy Phosphate Compounds: Free Energy Sources in Biological Systems 19) Based on the half reactions given below, which of the following reactants is the strongest reducing agent? A) NADH NAD+ + H+ + 2e- (E = + 0.32 V) B) dihydrolipoic acid lipoic acid + 2H+ + 2e- (E = + 0.29 V) C) FADH2 FAD + 2H+ + 2e- (E = + 0.22 V) D) lactate pyruvate + 2H+ + 2e- (E = + 0.18 V) E) succinate fumarate + 2H+ + 2e- (E = - 0.03 V) Answer: A Difficulty: 1 Topic: G for Oxidation/Reduction Reactions 20) Which of the following reactions, if coupled to the reduction of -ketoglutarate, would give the most exergonic overall reaction? -ketoglutarate + CO2 + 2H+ + 2e- isocitrate (E = - 0.38 V) A) ubiquinol ubiquinone + 2H+ + 2e- (E = - 0.04 V) B) FADH2 FAD + 2H+ + 2e- (E = + 0.22 V) C) NADH NAD+ + H+ + 2e- (E = + 0.32 V) D) H2 2H+ + 2e- (E = + 0.42 V) E) pyruvate + CoA acetyl CoA + CO2 + H+ + 2e- (E = + 0.48 V) Answer: E Difficulty: 2 Topic: G for Oxidation/Reduction Reactions 21) What is the E for the spontaneous reaction that would result if the following reactions were coupled? NAD+ + H+ + 2e- NADH E = -0.32 V pyruvate + 2H+ + 2e- lactate E = -0.19 V A) -0.51 V B) -0.13 V C) +0.13 V D) +0.51 V E) none of the above Answer: C Difficulty: 3 Topic: G for Oxidation/Reduction Reactions 22) In a resting muscle cell at 37 C, what is the G for the phosphorylation of ADP by creatine phosphate (CP) given the following concentrations: CP, 25 mM; ATP, 5 mM; ADP, 0.1 mM and creatine, 1 mM? creatine phosphate + H2O creatine + Pi G = -43.1 kJ/mol ATP + H2O ADP + Pi G = -30.5 kJ/mol A) +14.4 kJ/mol B) +10.8 kJ/mol C) -10.8 kJ/mol D) -14.4 kJ/mol E) none of the above Answer: C Difficulty: 3 Topic: Calculating Free Energy Changes for Biological Oxidations Under Nonequilibrium Conditions Short Answer Questions 1) 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 C? G1P + H2O glucose + Pi G = -20.9 kJ/mol G6P + H2O glucose + Pi G = -13.8 kJ/mol Answer: G1P G6P G = -7.1 kJ/mol G = -RT ln Q or Q = [G6P]/[G1P]= e(-G/RT) [G1P] = [G6P] / e(-G/RT) = 0.001 M / e(7100 J/mol/(8.314 J/molK)(310 K)) = 6.4 10-5 M [G1P] = 0.064 mM Difficulty: 3 Topic: Free Energy and Chemical Reactions: Chemical Equilibrium 2) If acetyl phosphate is made from the combination of ATP and acetate, what is the G? How would this reaction proceed within a typical cell? acetyl phosphate + H2O acetate + Pi + H+ G = -43.1 kJ/mol ATP + H2O ADP + Pi + H+ G = -30.5 kJ/mol Answer: G = +12.6 kJ/mol. If this reaction were to occur within a typical cell, the G for ATP hydrolysis is considerably more exergonic and is thus able to supply the necessary energy for the phosphorylation of acetate. Difficulty: 2 Topic: High Energy Phosphate Compounds: Free Energy Sources in Biological Systems 3) Calculate the G for the oxidation of succinate to fumarate, a step in the citric acid cycle. FAD + 2H+ + 2e- FADH2 E = - 0.22 V fumarate + 2H+ + 2e- succinate E = + 0.03 V Answer: E = - 0.25 V G = -nFE = -(2)(96.5 kJ/V/mol)(-0.25 V) = 48.3 kJ/mol Difficulty: 2 Topic: G for Oxidation/Reduction Reactions

Write a review

Your Name:


Your Review: Note: HTML is not translated!

Rating: Bad           Good

Enter the code in the box below:



 

Once the order is placed, the order will be delivered to your email less than 24 hours, mostly within 4 hours. 

If you have questions, you can contact us here