Biochemistry I- Rutgers Exam 1 UPDATED
ACTUAL Exam Questions and CORRECT
Answers
Which will show the greater degree of dissociation: formic acid (pKa = 3.75) or acetic acid (pKa
= 4.76) if dissolved in water at 0.1 M concentrations?
A. Formic acid C. Within the accuracy of measurement they will be equally dissociated. B.
Acetic acid D. Cannot tell from data given. - CORRECT ANSWER -A. Formic acid
Which will show the greater degree of dissociation: formic acid (pKa = 3.75) or acetic acid (pKa
= 4.76) if dissolved at 0.1 M concentrations in solutions whose pH is 11.0?
A. Formic acid C. Within the accuracy of measurement they will be equally dissociated. B.
Acetic acid D. Cannot tell from data given. - CORRECT ANSWER -C. Within the
accuracy of measurement they will be equally dissociated.
Which of the following experimental observations disproved the vitalist claim that the substances
of which living matter is composed are qualitatively different from those which compose the
non-living world?
A. the demonstration by the Buchner brothers that broken and therefore dead yeast cells could
convert sugar into ethanol B. the crystallization by Sumner of the enzyme urease C. Pasteur's
proof that living organisms arise only from other living organisms rather than by spontaneous
generation caused by the "vital force" D. Wöhler's synthesis of urea from ammonium cyanate E.
none of the above - CORRECT ANSWER -D. Wöhler's synthesis of urea from ammonium
cyanate
At pH 6.5 ribonuclease-A has a net charge of +4. At pH 2 the protein has a net charge of +19. If
the protein is dissolved in 0.1 M KCl at both pHs, and if the solution contains no other solutes, in
which case will the protein molecules have a larger number of chloride ions in their immediate
vicinity?
A. pH 2 C. a pH midway between 2 and 6.5 B. pH 6.5 D. It will have the same number of
chlorides at the two pHs. E. cannot tell from data given. - CORRECT ANSWER -A. PH 2
, The free energy of a reaction which is not at equilibrium, such as is the case in nearly all cellular
reactions, involves two terms: the standard free energy at equilibrium and a term expressing the
deviation of the actual
conditions from equilibrium. In the Henderson-Hasselbalch equation governing buffers, the
equivalent of the standard free energy term occurs at the pH at which
A. the weak acid is fully dissociated. D. half the weak acid is dissociated. B. the weak acid is
fully in the undissociated form. E. none of the above. C. the pH = the pI. - CORRECT
ANSWER -D. the weak acid is fully in the undissociated form
Which of the following is best described as an entropy driven reaction?
A. H = -82 kJ/mol, -TS = -136 kJ/mol D. none of the above is entropy driven B. H = -1367
kJ/mol, -TS = +41 kJ/mol E. all the above are entropy driven. C. H = +110 kJ/mol, -TS = -140
kJ/mol - CORRECT ANSWER -C. delta H= +110 kJ/mol
Rank the following vitalist statements in order of decreasing breadth of their claims about the
living world.
1. Living matter may be composed of the same materials as non-living matter, but organisms
arise from non-living matter by spontaneous generation by intervention of the "vital force." 2.
The substances composing living mater are qualitatively different from those of the non-living
world. 3. The structure of enzymes is too complex to be described in chemical terms, and the
nature of biological catalysis is not comprehensible. 4. We may be able to make some of the
substances of living matter, but the reactions which constitute life occur only in living cells.
A. 1,2,3,4 B. 4,3,2,1 C. 2,1,4,3 D. 3,2,4,1 E. none of these - CORRECT ANSWER -C. 2,
1, 4, 3
"Salting out" is a phenomenon in which addition of high concentrations of salt ions decreases the
solubility of a protein, causing it to precipitate. The precipitate contains many salt ions. Which of
the following is most likely to explain salting out?
ACTUAL Exam Questions and CORRECT
Answers
Which will show the greater degree of dissociation: formic acid (pKa = 3.75) or acetic acid (pKa
= 4.76) if dissolved in water at 0.1 M concentrations?
A. Formic acid C. Within the accuracy of measurement they will be equally dissociated. B.
Acetic acid D. Cannot tell from data given. - CORRECT ANSWER -A. Formic acid
Which will show the greater degree of dissociation: formic acid (pKa = 3.75) or acetic acid (pKa
= 4.76) if dissolved at 0.1 M concentrations in solutions whose pH is 11.0?
A. Formic acid C. Within the accuracy of measurement they will be equally dissociated. B.
Acetic acid D. Cannot tell from data given. - CORRECT ANSWER -C. Within the
accuracy of measurement they will be equally dissociated.
Which of the following experimental observations disproved the vitalist claim that the substances
of which living matter is composed are qualitatively different from those which compose the
non-living world?
A. the demonstration by the Buchner brothers that broken and therefore dead yeast cells could
convert sugar into ethanol B. the crystallization by Sumner of the enzyme urease C. Pasteur's
proof that living organisms arise only from other living organisms rather than by spontaneous
generation caused by the "vital force" D. Wöhler's synthesis of urea from ammonium cyanate E.
none of the above - CORRECT ANSWER -D. Wöhler's synthesis of urea from ammonium
cyanate
At pH 6.5 ribonuclease-A has a net charge of +4. At pH 2 the protein has a net charge of +19. If
the protein is dissolved in 0.1 M KCl at both pHs, and if the solution contains no other solutes, in
which case will the protein molecules have a larger number of chloride ions in their immediate
vicinity?
A. pH 2 C. a pH midway between 2 and 6.5 B. pH 6.5 D. It will have the same number of
chlorides at the two pHs. E. cannot tell from data given. - CORRECT ANSWER -A. PH 2
, The free energy of a reaction which is not at equilibrium, such as is the case in nearly all cellular
reactions, involves two terms: the standard free energy at equilibrium and a term expressing the
deviation of the actual
conditions from equilibrium. In the Henderson-Hasselbalch equation governing buffers, the
equivalent of the standard free energy term occurs at the pH at which
A. the weak acid is fully dissociated. D. half the weak acid is dissociated. B. the weak acid is
fully in the undissociated form. E. none of the above. C. the pH = the pI. - CORRECT
ANSWER -D. the weak acid is fully in the undissociated form
Which of the following is best described as an entropy driven reaction?
A. H = -82 kJ/mol, -TS = -136 kJ/mol D. none of the above is entropy driven B. H = -1367
kJ/mol, -TS = +41 kJ/mol E. all the above are entropy driven. C. H = +110 kJ/mol, -TS = -140
kJ/mol - CORRECT ANSWER -C. delta H= +110 kJ/mol
Rank the following vitalist statements in order of decreasing breadth of their claims about the
living world.
1. Living matter may be composed of the same materials as non-living matter, but organisms
arise from non-living matter by spontaneous generation by intervention of the "vital force." 2.
The substances composing living mater are qualitatively different from those of the non-living
world. 3. The structure of enzymes is too complex to be described in chemical terms, and the
nature of biological catalysis is not comprehensible. 4. We may be able to make some of the
substances of living matter, but the reactions which constitute life occur only in living cells.
A. 1,2,3,4 B. 4,3,2,1 C. 2,1,4,3 D. 3,2,4,1 E. none of these - CORRECT ANSWER -C. 2,
1, 4, 3
"Salting out" is a phenomenon in which addition of high concentrations of salt ions decreases the
solubility of a protein, causing it to precipitate. The precipitate contains many salt ions. Which of
the following is most likely to explain salting out?
