Possibly Helpful Information:
AA Amino Group Carboxyl Group R Group
Ala, Gly, Ile, Leu, Val 9.7 2.3
Asn, Gln 9.0 2.1
Met, Ser, Trp 9.3 2.3
Phe 9.1 1.8 2.0
Pro 10.6 2.6
Thr 10.4
Asp 9.8 2.1 3.9
Glu 9.7 2.2 4.2
His 9.2 1.8 6.0
Cys 10.8 1.8 2.2 8.3
Tyr 9.1 2.2 10.0
Lys 9.0 2.2 10.5
Arg 9.0 12.5
Kelvin = Celsius + 273
, Section 1: Multiple Choice. Select the best answer for each of the following questions. There is only one
correct answer per question.
1. When comparing the properties of H2O and H2S, we would expect:
a. H2O should have a higher melting point and higher boiling point than H2S.
b. H2O should have a higher melting point and lower boiling point than H2S.
c. H2O should have a lower melting point and higher boiling point than H2S.
d. H2O should have a lower melting point and lower boiling point than H2S.
2. The property that allows the functional group R-O-H to engage in hydrogen bonding is best attributed to
which of the following?
a. Hydrogen has a high electronegativity.
b. Oxygen has a high electronegativity.
c. Ionic bonds increase the stability of nearby groups.
d. Large electronegativity difference between Oxygen and Hydrogen.
3. Which of the following is a true statement?
a. A single hydrogen bond is stronger than a single covalent bond due to being an electrostatic
interaction.
b. The sum of all weak interactions can never be stronger than that of a single covalent bond. c.
Hydrogen bonding is unique to water.
d. The angle a hydrogen bond makes between its donor and acceptor influences the strength of the
hydrogen bond.
e. More than one of the above statements is true.
4. Geckos have “sticky feet” due to which of the following phenomena?
a. Random variations in where the electrons are around a nucleus, resulting in an induced dipole
when two atoms are in close contact and causing attraction.
b. Hydrogen bonding between the Gecko’s feet and the material caused by electronegativity
differences.
c. Transient covalent bonding allows the Gecko to be able to “stick” to other surfaces via amino
acid residues in its feet.
d. Gecko have very large, hydrophobic feet that are attracted to surfaces via the hydrophobic effect.
5. The hydrophobic effect is best attributed to…
a. Entropy.
b. Temperature.
c. Electrostatic attraction.
d. Non-electrostatic attraction.