Chapter 4: Carbon and the Molecular Diversity of Life
Chapter Quiz
1 . At the beginning of the 19th century, it was thought that the substances that made up living things were special and could not be synthesized by ordinary chemical methods. This now-discarded theory was called the theory of _____. (Concept 4.1) [Hint]
special creation
spontaneous generation
vitalism
materialism
mechanism
2 . The first organic molecule to be synthesized from inorganic substances was _____. (Concept 4.1) [Hint]
urea
acetic acid
ammonium cyanate
insulin
DNA
3 . Stanley Miller's experiments were significant because he demonstrated that _____. (Concept 4.1) [Hint]
the behavior of any molecule containing a carbon atom was fundamentally the same
under certain circumstances the theory of vitalism was valid
a variety of simple organic compounds could be spontaneously synthesized from components in Earth's primitive atmosphere
lightning discharges could produce the molecules previously presumed to have originated in volcanic outgassings
urea could be synthesized from entirely naturally occurring salts
4 . Which is an organic molecule? (Concept 4.2) [Hint]
Ne
O2
CH4
NaCl
H2O
5 . Which element is most particularly associated with organic chemistry? (Concept 4.2) [Hint]
carbon
sulfur
nitrogen
hydrogen
oxygen
6 . What is the three-dimensional shape created by hybrid orbitals that are formed when a carbon atom is covalently bonded with four other atoms? (Concept 4.2) [Hint]
a flat sheet with carbon in the center
a triangle with carbon in the center
a cube with carbon in the center
a tetrahedron with carbon in the center
All of the above are possible.
7 . A straight-chain carbon compound constructed from _____ must contain at least one carbon-carbon double bond. (Concept 4.2) [Hint]
6 hydrogen, 2 carbon
6 hydrogen, 3 carbon
6 hydrogen, 2 carbon, 1 oxygen
8 hydrogen, 3 carbon, 3 oxygen
14 hydrogen, 6 carbon
8 . Carbon atoms are the most versatile building blocks of the molecules used by living organisms because _____. (Concept 4.2) [Hint]
carbon is the central atom of carbon dioxide, a necessary molecule for photosynthesis
carbon is the central atom in urea, a molecule used by many living organisms to transport wastes from the body
each carbon atom acts as an intersection point from which a molecule can branch off in up to four directions
carbon can combine with hydrogen to form hydrocarbons
all of the above
9 . The carbon atom is tetravalent; this means that _____. (Concept 4.2) [Hint]
carbon readily forms ionic bonds
carbon's first electron shell holds 4 electrons
a carbon atom can complete its valence shell by forming four covalent bonds
the bond angle between each bond is 90o, forming an arrangement like the points on a compass
carbon has a total of 4 electrons
10 . A molecule has one carbon-carbon double bond and four monovalent atoms or groups. How many different geometric isomers exist for this molecule? (Concept 4.2) [Hint]
none
two
four
six
eight
11 . The two compounds
are related to each other by being _____. (Concept 4.2) [Hint]
hydrocarbons
organic compounds
isomers
double-bonded compounds
all of the above
12 . Which of the following functional groups is present in all amino acids? (Concept 4.3) [Hint]
-SH
-COH
-OH
-NH2
-OPO3-2
13 . Which of these is found in all amino acids? (Concept 4.3) [Hint]
-COOH
-COH
-OH
-NH2
Both -COOH and -NH2
14 . Freon, CCl2F2, is _____ because _____. (Concept 4.2) [Hint]
a structural isomer…there are several possible covalent arrangements
a geometric isomer…free rotation about the bond axis is not possible
an enantiomer…the carbon is asymmetric
an enantiomer…the molecule exists in two mirror-image configurations
not an isomer…there is only one structural configuration for the molecule
15 . Glucose and hexanoic acid each contain six carbon atoms, but they have completely different properties. Glucose is a nutrient found in food; hexanoic acid is poisonous. Their differences must be due to different _____. (Concept 4.3) [Hint]
monomers
macromolecules
isomers
quaternary structures
functional groups
16 . Although the structures of the functional groups that are most important to life vary, they share one thing in common: They _____. (Concept 4.3) [Hint]
all contain oxygen
all have at least one double bond
always cause the carbon to which they are attached to become an asymmetric carbon, thus they convert the molecule into an enantiomer
all are hydrophilic and increase the organic compound's water solubility
force straight chains of carbons into closed rings of carbon
17 . Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they _____. (Concept 4.3) [Hint]
all share the same functional group: a hydroxyl
are soluble in water
are hydrophobic
all contain a carbonyl group
increase the acidity of solutions
18 . Which one of the following molecules has a carboxyl functional group? (Concept 4.3) [Hint]
R-NH2
R-COH
R-COOH
R-OPO3-2
R-SH
19 . Which one of the following molecules is a weak base? (Concept 4.3) [Hint]
R-NH2
R-SH
R-OH
R-COOH
none of the above
20 . Which of the following molecules is a weak acid? (Concept 4.3) [Hint]
R-NH2
R-SH
R-OH
R-COOH
none of the above
21 . Which one of the following functional groups increases the solubility of organic compounds in water? (Concept 4.3) [Hint]
-SH
-COOH
-COH
-NH2
all of the above
22 . Which of the following examples describes a unique functional property of the carboxyl group? (Concept 4.3) [Hint]
Its compounds may be structural isomers with different properties.
Two groups can interact to help stabilize protein structure.
It is polar as a result of the electronegative oxygen atom drawing electrons toward itself.
The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate reversibly.
It acts as a base.
23 . Which of the following functional groups is associated with a release of energy that cells can harvest to perform many functions? (Concept 4.3) [Hint]
amino
phosphate
sulfhydryl
hydroxyl
carboxyl
24 . Which functional group would you predict is part of abscisic acid (ABA)? (Concept 4.3) [Hint]
carboxyl
hydroxyl
carbonyl
amino
sulfhydryl
25 . The ionized or dissociated carboxyl group may be written as _____. (Concept 4.3) [Hint]
-COOH
-OH
-COO-
NH4+
-C=O
26 . Which one of the following groups would not be capable of hydrogen bonding with an oxygen atom on another functional group? (Concept 4.3) [Hint]
amino
hydroxyl
carboxylic acid
sulfhydryl
none of the above
27 . Choose the pair of terms that complete this sentence about functional groups in organic chemistry: Carboxyl is to ______ as ______ is to base. (Concept 4.3) [Hint]
acid…carbonyl
sulfhydryl…carbonyl
acid…amino
hydroxyl…amino
ketone…phosphate
28 . Which of these is a thiol? (Concept 4.3) [Hint]
-SH
-COH
-OH
-NH2
none of the above
©2005 Pearson Education, Inc., publishing as Benjamin Cummings
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