BIOCHEM 384
BIOC 384 - D2Q 1-3 2023 – MIESFELD EXAM
QUESTIONS AND ANSWERS
1. Which TWO of the following processes are driven by the hydrophobic effect?
1. Dissolving sodium chloride in water
2. Sequestration of hydrophobic groups to the interior of a folded protein
3. Melting of ice
4. Separation of oil and water
2. Sequestration of hydrophobic groups to the interior of a folded protein
4. Separation of oil and water
2. What type of solution should erythrocytes (red blood cells) be stored in to prevent
damage?
1. Hypersonic solution
2. Hypotonic solution
3. Solution at the same pH
4. Isotonic solution
5. Hypertonic solution
4. Isotonic solution
3. The evolution of antifreeze proteins is an example of proteins that are:
1. Similar in function and similar in structure
2. Different in structure, but similar in function
3. Different in function, but similar in structure
4. Different in structure and different in function
2. Different in structure, but similar in function
4. A titratable group is in the active site of an enzyme and must be protonated for the
enzyme to function. Assume that the group has a pKa of 6.5 and that the activity is
proportional to the fraction of molecules in the protonated state. Which FOUR of the
following statements are true?
1. At pH 9.0 close to 100% of the enzyme molecules are active.
2. At pH 6.8 the enzyme is 66.6% inactive.
3. At pH 6.5 the enzyme is 50% active.
4. At pH 7.2 there are about 5 inactive enzymes for every active enzyme.
5. At pH 9.0 close to 100% of the enzyme molecules are inactive.
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2. At pH 6.8 the enzyme is 66.6% inactive
3. At pH 6.5 the enzyme is 50% active.
4. At pH 7.2 there are about 5 inactive enzymes for every active enzyme.
5. At pH 9.0 close to 100% of the enzyme molecules are inactive.
5. Which of the following equations describes the equilibrium reaction: aA + bB ↔ cC +
dD?
1. Keq = c[C]d[D] / a[A]b[B]
2. Keq = [C]c[D]d / [A]a[B]b
3. Keq = [A]a[B]b / [C]c[D]d
4. Keq= ΔG°' = -RT log ΔG
2. Keq = [C]c[D]d / [A]a[B]b
6. Which mathematical equation below describes the reaction A + B ↔ C + D?
1. Keq = [C][D]/[A][B]
2. ΔG° = -RT log Keq
3. Keq = [A][B]/[C][D]
4. ΔG° = RT ln Keq
1. Keq = [C][D]/[A][B]
7. In aerobic respiration, the reductant (reducing agent) is ________________and the
oxidant (oxidizing agent) is _______________with carbon dioxide being one of the
products and _____________being the other product. The conversion of
________________energy to chemical energy generates ATP for use in metabolism.
Glucose, oxygen, water, redox
8. The energy change in a system is related to the amount of heat transferred and work
done. If there is no heat transferred, what is the magnitude of the work in a system equal
to?
1. Only the final energy of the system (Efinal).
2. Energy change in the system (delta Esystem = Efinal - Einitial).
3. Only the initial energy of the system (Einitial).
4. Total energy in the universe (delta Euniverse = Einitial + Etotal).
5. Energy change in the universe (delta Euniverse = Einitial - Etotal).
2. Energy change in the system (delta Esystem = Efinal - Einitial).
9. Choose the two correct answers below that most accurately describe the difference
between the actual change in free energy (delta G) and the standard change in free energy
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(delta G°").
1. The actual change in free energy is dependent on temperature whereas the standard
change in free energy is dependent on pressure but not temperature.
2. The standard change in free energy reflects the potential energy in reactants and
products independent of concentration whereas the actual change in free energy is
dependent on the concentration of reactants and products under steady state conditions.
3. The standard change of free energy is a function of time whereas the actual change in
free energy is a function of the rate constant.
4. There is no difference between the actual change in free energy and the standard
change in free energy as long as the concentration of H20 is 55 M.
5. The actual change in free energy changes in response to the environment whereas the
standard change in free energy is a constant for a given reaction.
2. The standard change in free energy reflects the potential energy in reactants and
products independent of concentration whereas the actual change in free energy is
dependent on the concentration of reactants and products under steady state conditions.
5. The actual change in free energy changes in response to the environment whereas the
standard change in free energy is a constant for a given reaction.
10. The following are five hypothetical reactions:
1. A <-> B -5 kJ/mol
2. B <-> C + D +8 kJ/mol
3. B <-> E -10 kJ/mol
4. E <-> F +5 kJ/mol
5. D <-> F +1 kJ/mol
Two distinct metabolic pathways are possible by combining these reactions, of which
only one of these pathways is energetically favorable. Which pathway below is the
correct energetically favorable pathway?
A. A<-->B<-->C + D<-->E<-->F
B.. A<-->B<-->C<-->D-->F
C. A<-->C<-->D<-->E<-->F
D. A<-->B<-->E<-->F
D. A<-->B<-->E<-->F
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11. What happens to an organism if it is no longer able to convert energy from the
environment (nutrients or sunlight) into chemical energy?
1. it reaches equilibrium with the environment and goes to sleep
2. it converts from being a heterotroph to an autotroph
3. it uses 100 kJ/mol of standard free energy to regenerate
4. it reaches equilibrium with the environment and dies
4. it reaches equilibrium with the environment and dies
12. Calculate the energy charge of the cell assuming that the concentration of ATP, ADP,
and AMP were all equal to 10 mM. Why is this value not a good representation of actual
energy charge in a healthy cell?
1. EC = 0.7; because ATP levels are normally lower and AMP levels are normally lower
2. EC = 1.0; because ATP levels are normally higher and AMP levels are normally lower
3. EC = 0.9; because ATP lev
4. els are normally lower and AMP levels are normally higher
5. EC = 0.5; because ATP levels are normally higher and AMP levels are normally lower
5. EC = 0.5; because ATP levels are normally higher and AMP levels are normally lower
13. In the following set of reactions, which reactant is the shared intermediate?
A+B+C →D
D+E→F
1. D
2. E
3. F
4. A
5. B
6. C
1. D
14. Calculate the delta G value for the conversion of 2-phosphoglycerate to
phosphoenolpyruvate by the enzyme enolase at 25ºC when the concentration of 2-
phosphoglycerate is 10 times higher than the concentration of phosphoenolpyruvate. The
biochemical standard free energy change (delta Gº') for this reaction is +1.7 kJ/mol.
1. -4.0 kJ/mol
2. +2.6 kJ/mol
3. +1.2 kJ/mol
BIOCHEM 384
BIOC 384 - D2Q 1-3 2023 – MIESFELD EXAM
QUESTIONS AND ANSWERS
1. Which TWO of the following processes are driven by the hydrophobic effect?
1. Dissolving sodium chloride in water
2. Sequestration of hydrophobic groups to the interior of a folded protein
3. Melting of ice
4. Separation of oil and water
2. Sequestration of hydrophobic groups to the interior of a folded protein
4. Separation of oil and water
2. What type of solution should erythrocytes (red blood cells) be stored in to prevent
damage?
1. Hypersonic solution
2. Hypotonic solution
3. Solution at the same pH
4. Isotonic solution
5. Hypertonic solution
4. Isotonic solution
3. The evolution of antifreeze proteins is an example of proteins that are:
1. Similar in function and similar in structure
2. Different in structure, but similar in function
3. Different in function, but similar in structure
4. Different in structure and different in function
2. Different in structure, but similar in function
4. A titratable group is in the active site of an enzyme and must be protonated for the
enzyme to function. Assume that the group has a pKa of 6.5 and that the activity is
proportional to the fraction of molecules in the protonated state. Which FOUR of the
following statements are true?
1. At pH 9.0 close to 100% of the enzyme molecules are active.
2. At pH 6.8 the enzyme is 66.6% inactive.
3. At pH 6.5 the enzyme is 50% active.
4. At pH 7.2 there are about 5 inactive enzymes for every active enzyme.
5. At pH 9.0 close to 100% of the enzyme molecules are inactive.
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2. At pH 6.8 the enzyme is 66.6% inactive
3. At pH 6.5 the enzyme is 50% active.
4. At pH 7.2 there are about 5 inactive enzymes for every active enzyme.
5. At pH 9.0 close to 100% of the enzyme molecules are inactive.
5. Which of the following equations describes the equilibrium reaction: aA + bB ↔ cC +
dD?
1. Keq = c[C]d[D] / a[A]b[B]
2. Keq = [C]c[D]d / [A]a[B]b
3. Keq = [A]a[B]b / [C]c[D]d
4. Keq= ΔG°' = -RT log ΔG
2. Keq = [C]c[D]d / [A]a[B]b
6. Which mathematical equation below describes the reaction A + B ↔ C + D?
1. Keq = [C][D]/[A][B]
2. ΔG° = -RT log Keq
3. Keq = [A][B]/[C][D]
4. ΔG° = RT ln Keq
1. Keq = [C][D]/[A][B]
7. In aerobic respiration, the reductant (reducing agent) is ________________and the
oxidant (oxidizing agent) is _______________with carbon dioxide being one of the
products and _____________being the other product. The conversion of
________________energy to chemical energy generates ATP for use in metabolism.
Glucose, oxygen, water, redox
8. The energy change in a system is related to the amount of heat transferred and work
done. If there is no heat transferred, what is the magnitude of the work in a system equal
to?
1. Only the final energy of the system (Efinal).
2. Energy change in the system (delta Esystem = Efinal - Einitial).
3. Only the initial energy of the system (Einitial).
4. Total energy in the universe (delta Euniverse = Einitial + Etotal).
5. Energy change in the universe (delta Euniverse = Einitial - Etotal).
2. Energy change in the system (delta Esystem = Efinal - Einitial).
9. Choose the two correct answers below that most accurately describe the difference
between the actual change in free energy (delta G) and the standard change in free energy
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(delta G°").
1. The actual change in free energy is dependent on temperature whereas the standard
change in free energy is dependent on pressure but not temperature.
2. The standard change in free energy reflects the potential energy in reactants and
products independent of concentration whereas the actual change in free energy is
dependent on the concentration of reactants and products under steady state conditions.
3. The standard change of free energy is a function of time whereas the actual change in
free energy is a function of the rate constant.
4. There is no difference between the actual change in free energy and the standard
change in free energy as long as the concentration of H20 is 55 M.
5. The actual change in free energy changes in response to the environment whereas the
standard change in free energy is a constant for a given reaction.
2. The standard change in free energy reflects the potential energy in reactants and
products independent of concentration whereas the actual change in free energy is
dependent on the concentration of reactants and products under steady state conditions.
5. The actual change in free energy changes in response to the environment whereas the
standard change in free energy is a constant for a given reaction.
10. The following are five hypothetical reactions:
1. A <-> B -5 kJ/mol
2. B <-> C + D +8 kJ/mol
3. B <-> E -10 kJ/mol
4. E <-> F +5 kJ/mol
5. D <-> F +1 kJ/mol
Two distinct metabolic pathways are possible by combining these reactions, of which
only one of these pathways is energetically favorable. Which pathway below is the
correct energetically favorable pathway?
A. A<-->B<-->C + D<-->E<-->F
B.. A<-->B<-->C<-->D-->F
C. A<-->C<-->D<-->E<-->F
D. A<-->B<-->E<-->F
D. A<-->B<-->E<-->F
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11. What happens to an organism if it is no longer able to convert energy from the
environment (nutrients or sunlight) into chemical energy?
1. it reaches equilibrium with the environment and goes to sleep
2. it converts from being a heterotroph to an autotroph
3. it uses 100 kJ/mol of standard free energy to regenerate
4. it reaches equilibrium with the environment and dies
4. it reaches equilibrium with the environment and dies
12. Calculate the energy charge of the cell assuming that the concentration of ATP, ADP,
and AMP were all equal to 10 mM. Why is this value not a good representation of actual
energy charge in a healthy cell?
1. EC = 0.7; because ATP levels are normally lower and AMP levels are normally lower
2. EC = 1.0; because ATP levels are normally higher and AMP levels are normally lower
3. EC = 0.9; because ATP lev
4. els are normally lower and AMP levels are normally higher
5. EC = 0.5; because ATP levels are normally higher and AMP levels are normally lower
5. EC = 0.5; because ATP levels are normally higher and AMP levels are normally lower
13. In the following set of reactions, which reactant is the shared intermediate?
A+B+C →D
D+E→F
1. D
2. E
3. F
4. A
5. B
6. C
1. D
14. Calculate the delta G value for the conversion of 2-phosphoglycerate to
phosphoenolpyruvate by the enzyme enolase at 25ºC when the concentration of 2-
phosphoglycerate is 10 times higher than the concentration of phosphoenolpyruvate. The
biochemical standard free energy change (delta Gº') for this reaction is +1.7 kJ/mol.
1. -4.0 kJ/mol
2. +2.6 kJ/mol
3. +1.2 kJ/mol
BIOCHEM 384
