BIOCHEMISTRY 3304 FINAL EXAM QUESTIONS AND CORRECT ANSWERS 2024
1 What is the primary fact about evolution?
a. Natural selection.
b. Theory about how organisms change over time to adapt to new environment.
c. Observation that organisms change over time.
d. a and c
2 Which statement(s) refer to the First Law of Thermodynamics?
a. The total energy of any entire system must be conserved.
b. The total energy of a system increases in a spontaneous reaction.
c. The disorder of the universe increases in a spontaneous reaction.
d. The disorder of the universe cannot increase in a spontaneous reaction.
3 For spontaneous reaction, which of the statements is true at any temperature. G = H – T S
a. H is negative, enthalpically disfavored and S is positive, entropically disfavored
b. H is positive, enthalpically disfavored and S is positive, entropically disfavored
c. H is negative, enthalpically disfavored and S is negative, entropically disfavored
d. H is positive, enthalpically disfavored and S is negative, entropically disfavored
4 The Go for a reaction A B at standard temperature is 20.1 kJ/mol. If the starting concentration
of B is 100 and A is 10, what is the G for the reaction as written at standard temperature?
a. +14.4 kJ/mol
b. +25.8 kJ/mol
c. -14.4 kJ/mol
d. -25.8 kJ/mol
5 Water can apparently donate protons faster than the diffusion limit (faster than a single proton can
diffuse across a distance). What important property of water might explain this?
a. Water can accept and donate protons during catalytic biological reactions.
b. Water has both hydrogens and lone-pair electrons that can form hydrogen bonding networks.
c. The density of water decreases upon freezing.
d. All of the above
6 What is the thermodynamic basis for the hydrophobic effect?
a. The organization of water molecules around a hydrophobic molecule.
b. The aggregation of hydrophobic molecules in water to reduce the number of water molecules
necessary to solubilize the hydrophobic molecules.
c. The entropy gained by releasing water molecules into bulk solvent through sequestering hydrophobic
molecules together.
d. All of the above.
7 If you want to remove salts from a protein solution, which of the following properties would you use?.
a. Diffusion
b. Osmosis
c. Dialysis
d. None of the above
8 You have these buffers: MES (pKa =6.09), MOPS (pKa =7.15), Tris (pKa =8.08) and Piperidine (pKa
=11.12). While purifying a protein, which buffer would you prefer if you had to maintain pH at 7.8.
, a. MES
b. MOPS
c. Tris
d. Piperidine
9 You want to have 1000 ml of 0.1M HEPES buffer at pH 7.17. The pKa for HEPES buffer is 7.47.
Approximately how much HEPES in acidic and basic form would you need to make this buffer? HINT:
HEPES-H+ is the acidic version of HEPES.
a. 66 millimoles of HEPES-H+ and 33 millimoles of HEPES
b. 50 millimoles of HEPES-H+ and 50 millimoles of HEPES
c. 33 millimoles of HEPES-H+ and 66 millimoles of HEPES
d. 10 millimoles of HEPES-H+ and 90 millimoles of HEPES
10 Identify the following amino acids?
a. P, R, W, M
b. P, F, Q, H
c. E, K, Y, S
d. E, R, W, T
11 In the following peptide, what is the chirality of serine and glutamic acid?
a. D-Ser, L-Glu
b. L-Ser, L-Glu
c. D-Ser, D-Glu
d. L-Ser, D-Glu
1 What is the primary fact about evolution?
a. Natural selection.
b. Theory about how organisms change over time to adapt to new environment.
c. Observation that organisms change over time.
d. a and c
2 Which statement(s) refer to the First Law of Thermodynamics?
a. The total energy of any entire system must be conserved.
b. The total energy of a system increases in a spontaneous reaction.
c. The disorder of the universe increases in a spontaneous reaction.
d. The disorder of the universe cannot increase in a spontaneous reaction.
3 For spontaneous reaction, which of the statements is true at any temperature. G = H – T S
a. H is negative, enthalpically disfavored and S is positive, entropically disfavored
b. H is positive, enthalpically disfavored and S is positive, entropically disfavored
c. H is negative, enthalpically disfavored and S is negative, entropically disfavored
d. H is positive, enthalpically disfavored and S is negative, entropically disfavored
4 The Go for a reaction A B at standard temperature is 20.1 kJ/mol. If the starting concentration
of B is 100 and A is 10, what is the G for the reaction as written at standard temperature?
a. +14.4 kJ/mol
b. +25.8 kJ/mol
c. -14.4 kJ/mol
d. -25.8 kJ/mol
5 Water can apparently donate protons faster than the diffusion limit (faster than a single proton can
diffuse across a distance). What important property of water might explain this?
a. Water can accept and donate protons during catalytic biological reactions.
b. Water has both hydrogens and lone-pair electrons that can form hydrogen bonding networks.
c. The density of water decreases upon freezing.
d. All of the above
6 What is the thermodynamic basis for the hydrophobic effect?
a. The organization of water molecules around a hydrophobic molecule.
b. The aggregation of hydrophobic molecules in water to reduce the number of water molecules
necessary to solubilize the hydrophobic molecules.
c. The entropy gained by releasing water molecules into bulk solvent through sequestering hydrophobic
molecules together.
d. All of the above.
7 If you want to remove salts from a protein solution, which of the following properties would you use?.
a. Diffusion
b. Osmosis
c. Dialysis
d. None of the above
8 You have these buffers: MES (pKa =6.09), MOPS (pKa =7.15), Tris (pKa =8.08) and Piperidine (pKa
=11.12). While purifying a protein, which buffer would you prefer if you had to maintain pH at 7.8.
, a. MES
b. MOPS
c. Tris
d. Piperidine
9 You want to have 1000 ml of 0.1M HEPES buffer at pH 7.17. The pKa for HEPES buffer is 7.47.
Approximately how much HEPES in acidic and basic form would you need to make this buffer? HINT:
HEPES-H+ is the acidic version of HEPES.
a. 66 millimoles of HEPES-H+ and 33 millimoles of HEPES
b. 50 millimoles of HEPES-H+ and 50 millimoles of HEPES
c. 33 millimoles of HEPES-H+ and 66 millimoles of HEPES
d. 10 millimoles of HEPES-H+ and 90 millimoles of HEPES
10 Identify the following amino acids?
a. P, R, W, M
b. P, F, Q, H
c. E, K, Y, S
d. E, R, W, T
11 In the following peptide, what is the chirality of serine and glutamic acid?
a. D-Ser, L-Glu
b. L-Ser, L-Glu
c. D-Ser, D-Glu
d. L-Ser, D-Glu
