Question 1
2 / 2 pts
Which of the following functional groups has two hydrogen bond donors and one hydrogen bond
acceptor?
thiol
C !
amine
ester
alcohol
amide
Question 2
2 / 2 pts
Hydrogen bonds are approximately ________% of the bond strength of covalent C-C or C-H
bonds.
20
1
C !
5
95
50
Question 3
2 / 2 pts
Which of the following is an example of the hydrophobic effect?
oil sheens seen on the ocean following an oil spill
the lipid membrane of cells and organelles
protein folding that places hydrophobic amino acids in the interior of the protein
the separation of salad dressing
C !
all of the above
Question 4
0 / 2 pts
Due to the formation of hydrogen bonds, ________ is highly soluble in water.
Y A
sodium chloride
carbon dioxide
octane
Correct Answer
methanol
cholesterol
Question 5
2 / 2 pts
Which of the following molecules would be prevented from readily crossing a lipid bilayer?
sodium ions
potassium ions
water
glucose
C !
all of the above
Question 6
2 / 2 pts
Which of the following is an example of an amphipathic molecule?
C !
palmitic acid, a fatty acid
adenine, a base found in nucleic acids
glucose, a monosaccharide
serine, an amino acid
none of the above
Question 7
2 / 2 pts
Which of the following shows the buffer that is found in the blood stream?
H3PO4 ⇌ H2PO4
2- + H+
C !
H2CO3 ⇌ HCO3
- + H+
HPO4
2- ⇌ PO4
3- + H+
H2PO4
- ⇌ HPO4
2- + H+
HCO3
- ⇌ CO3
2- + H+
Question 8
2 / 2 pts
Which of the following explains how nucleotides might have polymerized into nucleic acids in
the prebiotic world?
a mixture of hydrogen cyanide, formaldehyde and phosphate can form nucleotides in the
presence of an electrical discharge
catalysts such as iron sulfide allow for the formation of new C–C bonds
C !
nucleotides used the surface of clay as a catalyst to form polymers
nucleotides formed short polymers in the high temperatures of hydrothermal vents
all of the above
Question 9
2 / 2 pts
Fatty acid anions most commonly assemble into ________ in aqueous solution.
liposomes
C !
micelles
lipid bilayers
solvent-filled vesicles
none of the above
Question 10
2 / 2 pts
Urea is a water-soluble product of nitrogen metabolism. How many hydrogen bonds can one urea
molecule donate to surrounding water molecules?
5
2
6
3
C !
4
Question 11
2 / 2 pts
Which of the following biopolymers is correctly paired with the bond that forms between the
monomers?
DNA: phosphate bond
C !
polysaccharide: glycosidic bond
protein: ester bond
RNA: phosphate bond
all of the above
Question 12
2 / 2 pts
A gaseous mixture of hydrogen, water, ammonia and methane can produce which of the
biomolecules when exposed to an electrical discharge (such as lightning)?
carbohydrates
C !
amino acids
lipids
nucleotides
none of the above
Question 13
2 / 2 pts
A spontaneous process always has ________.
ΔH > 0
ΔG > 0
ΔH < 0
C !
ΔG < 0
none of the above
Question 14
2 / 2 pts
The similarity of one organism to another (for example a bacteria versus a human) is most easily
done by comparing which biopolymer?
proteins
C !
nucleic acids
polysaccharides
lipids
all of the above
Question 15
2 / 2 pts
When a non-polar substance is added to water, how do the molecules of water behave?
the regular hydrogen bond pattern is disrupted resulting in an increase of entropy
the regular hydrogen bond pattern is disrupted resulting in an increase of enthalpy
the regular hydrogen bond pattern is disrupted resulting in a decrease of enthalpy
C !
the regular hydrogen bond pattern is disrupted resulting in a decrease of entropy
none of the above
Question 16
2 / 2 pts
The biological classification system categorizes organisms into which of the following domains?
bacteria and eukarya
prokarya and eukarya
archaea and eukarya
C !
bacteria, archaea and eukarya
bacteria, eukarya and prokarya
Question 17
2 / 2 pts
Which of the following molecules contains the most oxidized form of carbon?
acetaldehyde
acetic acid
C !
carbon dioxide
ethanol
ethylene
Question 18
2 / 2 pts
During vigorous exercise, hydrogen ions are produced within cells as a result of increased
metabolism. What component of the intracellular buffer would increase as a result of the
increased H+ production?
PO4
3-
H3PO4
C !
H2PO4
-
HPO4
2-
none of the above
Question 19
2 / 2 pts
Metabolic acidosis often causes increased respiratory rates. What portion of the bloodstream
buffer is lost through increased respiration?
H+
H2CO3
H2O
HCO3
-
C !
CO2
Question 20
2 / 2 pts
Molecules such as methanol and ethanol are very soluble in water because ________.
C !
they contain O─H groups that can form multiple H-bonds with water
they do not form intermolecular H-bonds
they contain C─H groups that donate H-bonds to water
they tend to avoid contact with each other
they contain C─H groups that accept H-bonds from water
Question 21
2 / 2 pts
A reaction with a ________ ΔH and a ________ ΔS will never be spontaneous.
positive; positive
negative; positive
C !
positive; negative
negative; negative
none of the above
Question 22
2 / 2 pts
Considering the energetics of transferring nonpolar molecules from water to a nonpolar solvent,
the factor TΔS is generally ________, causing ΔG to be ________.
negligible; either positive or negative
positive; positive
negative; positive
negative; negative
C !
positive; negative
Question 23
0 / 2 pts
The second law of thermodynamics states ________.
that spontaneous processes are characterized by the conversion of work to force
that nonspontaneous processes are characterized by the conversion of order to disorder
Correct Answer
that spontaneous processes are characterized by the overall conversion of order to disorder
that spontaneous processes are characterized by the conversion of heat to pressure
Y A
none of the above
Question 24
2 / 2 pts
Hydrophobic interactions between nonpolar molecules ________.
are the result of strong attractions between nonpolar molecules
C !
require the presence of surrounding water molecules
depend on strong permanent dipoles in the nonpolar molecules
are the result of strong repulsion between water and nonpolar molecules
result from the tendency of water to maximize contact with nonpolar molecules
Question 25
2 / 2 pts
Hydrogen bonds within liquid water are ________.
attractions between two oxygen atoms
attractions between the protons of the oxygen nuclei
attractions between the H+ and −OH ions of the liquid
ion-induced dipole interactions
C !
dipole-dipole interactions
Question 26
2 / 2 pts
Which of the following is true regarding hydrophobic interactions between nonpolar molecules
or groups?
they are the result of strong attractions between nonpolar regions
they are the result of strong repulsion between water and nonpolar regions
C !
they require the presence of surrounding water molecules
they result from the tendency to maximize water's contact with nonpolar molecules
they depend on strong permanent dipoles in the nonpolar molecules
Question 27
2 / 2 pts
The biochemical principle that organisms acquire, transform, store, and use energy requires that
cells be able to ________.
convert light into other forms of energy
extract heat from their environment
produce their own energy
use only one form of energy from their environment
C !
extract energy from their environment
Question 28
2 / 2 pts
Which of the following shows the intracellular buffer?
C !
H2PO4
- ⇌ HPO4
2- + H+
HCO3
- ⇌ CO3
2- + H+
H2CO3 ⇌ HCO3
- + H+
HPO4
2- ⇌ PO4
3- + H+
H3PO4 ⇌ H2PO4
2- + H+
Question 29
0 / 2 pts
Which of the following would be the strongest acid?
succinic acid, a diprotic acid with pK = 4.21 and 5.64
Correct Answer
formic acid, pK = 3.75
acetic acid, pK = 4.76
ammonium ion, pK = 9.25
Y A
cannot be determined from the given information
Question 30
2 / 2 pts
At any given moment, a single water molecule participates in ________ strong hydrogen
bond(s). The role played by the water molecule is best characterized as ________.
two; two H-bond acceptor
one; H-bond donor
one; H-bond acceptor
two; two H-bond donor
C !
two; one H-bond donor, one H-bond acceptor
Question 31
2 / 2 pts
Which of the following correctly identifies the progression from individual molecules to a
functioning multi-cellular organism?
molecules, cell, organelle, organ, organism
molecules, cell, organ, organelle, organism
C !
molecules, organelle, cell, organ, organism
molecules, organelle, organ, cell, organism
molecules, organ, organelle, cell, organism
Question 32
2 / 2 pts
In aqueous solution, globules of up to several thousand amphiphilic molecules arranged with the
hydrophilic groups on the surface and the hydrophobic groups buried in the center are called
________.
vacuoles
C !
micelles
bilayers
liposomes
none of the above
Question 33
2 / 2 pts
Which of the following explains the attractive forces between hydrophobic molecules in an
aqueous solution?
C !
there is no increase in attractive forces between nonpolar molecules in an aqueous environment
in an aqueous environment, London dispersion forces between hydrophobic molecules and water
become stronger
since nonpolar molecules do not form hydrogen bonds with hydrogen bonds with water, they can
form hydrogen bonds with other nonpolar molecules
in an aqueous environment, London dispersion forces between hydrophobic molecules become
stronger
none of the above
Question 34
2 / 2 pts
Which of the major types of biomolecules is never found in a polymeric form?
C !
lipids
amino acids
nucleotides
carbohydrates
none of the above
Question 35
2 / 2 pts
A molecule that has both a polar and nonpolar region is called ________.
endergonic
C !
amphiphilic
micelleic
a membrane
none of the above
Question 36
0 / 2 pts
What is the conjugate acid of H2PO4
-?
H2PO4
Correct Answer
H3PO4
PO4
3-
Y A
HPO4
2-
none of the above
Question 37
0 / 2 pts
Change in enthalpy (ΔH) is best defined as ________.
the measure of disorder in a system
the sum of heat absorbed and work done
the pressure change at constant temperature
Correct Answer
the heat content of a system
Y A
none of the above
Question 38
2 / 2 pts
What functional groups are present in the following molecule?
alcohol, amine, amide and carboxylic acid
amine, ketone and carboxylic acid
C !
amine, amide and carboxylic acid
amine and carboxylic acid
none of the above are correct
Question 39
2 / 2 pts
What term is used to describe the exclusion of nonpolar substances from an aqueous solution?
lipid effect
C !
hydrophobic effect
nonpolar effect
oil droplet effect
amphiphilic effect
Question 40
2 / 2 pts
Which of the following explains the interactions that occur between the atoms of water
molecules and the ions that form when sodium chloride dissolves in water?
C !
hydrogens interact with the chloride ion, oxygens interact with the sodium ion
oxygens interact with the sodium ion and the chloride ion
hydrogens interact with the sodium ion, oxygens interact with the chloride ion
hydrogens interact with the sodium ion and the chloride ion
