Chapter 4 Mastering Biology – Flashcards
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Vitalism gave way to mechanism, the view that _____.
physical and chemical laws govern living systems
life on Earth began by way of abiotic synthesis of organic compounds
there was a life force outside the jurisdiction of physical and chemical laws
carbon's ability to form four covalent bonds makes complex molecules possible
bond angles are unpredictable
answer
physical and chemical laws govern living systems
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When Stanley Miller applied heat and electrical sparks to a mixture of simple inorganic compounds such as methane, hydrogen gas, ammonia, and water vapor, what compounds were produced?
mostly hydrocarbons
simple organic compounds, amino acids, and hydrocarbons
only simple inorganic compounds
only simple organic compounds such as formaldehyde and cyanide
answer
simple organic compounds, amino acids, and hydrocarbons
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L-dopa is used to treat _____.
Marfan's syndrome
muscle sprains
Parkinson's disease
Alzheimer's disease
laryngitis
answer
Parkinson's disease
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What kind of effect does R-dopa have on Parkinson's disease?
It alleviates the symptoms.
At first it makes the symptoms worse but over the long term it alleviates the symptoms.
It makes the symptoms of Parkinson's disease worse.
None.
At first it alleviates the symptoms but over the long term it makes the symptoms worse.
answer
None.
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Enantiomers are molecules that _____.
are isomers that differ in the covalent partnerships between their atoms
contain a carboxyl group
are mirror images
contain an -OH group
differ in the arrangement of their molecules about a double bond
answer
are mirror images
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Geometric isomers are molecules that _____.
differ in their molecular formulas
differ in the arrangement of their atoms about a double bond
are mirror images
are isomers that differ in the covalent partnerships between their atoms
are isomers in which one of the molecules contains an amino group and the other contains a phosphate group
answer
differ in the arrangement of their atoms about a double bond
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Which of the following is a hydrocarbon?
CO2
H2CO3
CCl2F2
C3H8
C6H12O6
answer
C3H8
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Which of the following best describes cis-trans isomers?
They differ in the arrangement of covalent bonds and in covalent partners.
They have the same number of atoms of the same elements but different structures.
They are long chains of hydrogen and carbon atoms.
They are mirror images of each other.
They differ in their spatial arrangement around inflexible double bonds.
answer
They differ in their spatial arrangement around inflexible double bonds.
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A carbon atom is most likely to form what kind of bond(s) with other atoms?
covalent
hydrogen
ionic
ionic bonds, covalent bonds, and hydrogen bonds
answer
covalent
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Why are hydrocarbons insoluble in water?
They exhibit considerable molecular complexity and diversity.
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
They are less dense than water.
The majority of their bonds are polar covalent carbon-to-hydrogen linkages.
answer
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
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What determines whether a carbon atom's covalent bonds to other atoms are in a tetrahedral configuration or a planar configuration?
the presence or absence of bonds with oxygen atoms
the solvent in which the organic molecule is dissolved
the presence or absence of double bonds between the carbon atom and other atoms
the polarity of the covalent bonds between carbon and other atoms
answer
the presence or absence of double bonds between the carbon atom and other atoms
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Citric acid makes lemons taste sour. Which of the following is a functional group that would cause a molecule such as citric acid to be acidic?
carboxyl
hydroxyl
amino
carbonyl
hydrocarbon
answer
carboxyl
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A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound _____.
should dissolve in water
lacks an asymmetric carbon and is probably a fat or lipid
will not form hydrogen bonds with water
should dissolve in a nonpolar solvent
answer
should dissolve in water
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Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? Testosterone and estradiol _____.
have different functional groups attached to the same carbon skeleton
are cis-trans isomers but have the same molecular formula
are structural isomers but have the same molecular formula
are enantiomers of the same organic molecule
answer
have different functional groups attached to the same carbon skeleton
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Which statement about a methyl functional group is correct?
A methyl group is polar.
A methyl group consists of a carbon bonded to three hydrogen atoms.
A methyl group may be negatively charged.
answer
A methyl group consists of a carbon bonded to three hydrogen atoms.
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Which of the functional groups shown above is most likely to gain a proton and become positively charged?
The carboxyl group is most likely to gain a proton.
The hydroxyl group is most likely to gain a proton.
The amino group is most likely to gain a proton
answer
The amino group is most likely to gain a proton
explanation: An amino group acts as a base and can pick up protons from the surrounding medium, becoming positively charged.
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What is ATP's importance in the cell?
ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.
ATP can add phosphate groups, thereby releasing energy that can be used in cellular processes.
ATP contains a long hydrocarbon tail and is important in storing energy.
ATP is an important component of cell membranes because it is nonpolar and hydrophobic.
ATP stores energy in carbonyl groups. When a carbonyl group is removed, energy is released to be used in cellular processes.
answer
ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.
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What functional group is commonly used in cells to transfer energy from one organic molecule to another?
phosphate
amino
hydroxyl
carboxyl
sulfhydryl
answer
phosphate
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Which of the following functional groups is associated with a release of energy when removed from the carbon skeleton with water?
amino group
hydroxyl group
carboxyl group
phosphate group
sulfhydryl group
answer
phosphate group
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Which action could produce a carbonyl group?
the replacement of the -OH of a carboxyl group with hydrogen
the addition of a thiol to a hydroxyl
the replacement of the nitrogen of an amine with oxygen
the addition of a sulfhydryl to a carboxyl
the addition of a hydroxyl to a phosphate
answer
the replacement of the -OH of a carboxyl group with hydrogen
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The experiments of Wöhler, Kolbe, Miller, and other chemists invalidated the concept of vitalism by demonstrating that _____.
organic molecules could be produced apart from living organisms using inorganic materials
one organic substance could be transformed into another organic substance
carbon atoms were common in both living organisms and nonliving substances such as rocks and soil
complex organic substances are the result of a series of sequential synthetic reactions occurring in both living organisms and nonliving systems
tissues extracted from living organisms could still promote organic reactions
answer
organic molecules could be produced apart from living organisms using inorganic materials
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Which statement is true of hydroxyl groups?
(a) They ionize more often when bound to C=O than when bound to CH2.
(b) They are negative ions.
(c) All alcohols and sugars have them.
Both (a) and (c).
Both (a) and (b).
answer
Both (a) and (c).
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How does a carbonyl group differ from a carboxyl group?
A carbonyl group ionizes more readily than a carboxyl group.
A carbonyl group contains N; a carboxyl group doesn't.
A carbonyl group is polar; a carboxyl group is not polar.
A carboxyl group contains oxygen; a carbonyl group doesn't.
A carboxyl group contains H; a carbonyl does not.
answer
A carboxyl group contains H; a carbonyl does not.
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How does an aldehyde group differ from a ketone group?
The ketone is polar; the aldehyde isn't.
The aldehyde contains C=O; the ketone doesn't.
Aldehydes, but not ketones, have H bound to C=O.
The aldehyde is polar; the ketone isn't.
The ketone occurs in sugars; the aldehyde doesn't.
answer
Aldehydes, but not ketones, have H bound to C=O.
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Amino groups ...
(a) act as bases in water.
(b) contain nitrogen atoms.
(c) occur in proteins.
Just two of the preceding answers are true.
(a), (b), and (c).
answer
(a), (b), and (c).
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A phosphate group contains _________ oxygen atoms.
4
1
3
2
3 or 4, depending on ionization.
answer
4
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Which functional group has the most different ionized forms?
Carboxyl
Hydroxyl
Carbonyl
Phosphate
Sulfhydryl
answer
Phosphate
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A functional group on a molecule in solution carries two H atoms at pH 9 and three H atoms at pH 3. The functional group is probably. . .
sulfhydryl.
carbonyl.
phosphate.
amino.
carboxyl.
answer
amino.
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Which atom is most likely to have a δ + charge?
An O that is involved in a hydrogen bond.
The S in a sulfhydryl group.
An O in a carboxyl group.
The C in a carbonyl group.
The N in an amino group.
answer
The C in a carbonyl group.
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Non-ionized carboxyl groups cause a molecule to act as an acid because they ...
(a) donate H+ ions to water.
(b) take H+ from water.
(c) raise the pH of water.
Both (a) and (c).
None of the above.
answer
(a) donate H+ ions to water.
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Which statement about isomers is correct?
Enantiomers differ in biological activity.
Structural isomers differ in the position of double bonds within the molecule.
Cis-trans isomers are mirror image isomers.
answer
Enantiomers differ in biological activity.
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Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they __________.
increase the acidity of solutions
all contain a carbonyl group
are hydrophobic
are soluble in water
share the same functional group: a hydroxyl
answer
share the same functional group: a hydroxyl
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Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they __________.
are hydrophobic
increase the acidity of solutions
are soluble in water
share the same functional group: a hydroxyl
all contain a carbonyl group
answer
share the same functional group: a hydroxyl
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Molecules that have the same chemical formula (same numbers of each atom) but different three-dimensional shapes are called _____.
isotopes
hydrocarbons
isomers
enantiomers
functional groups
answer
isomers
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A molecule has one carbon-carbon double bond and four monovalent atoms or groups. How many different cis-trans isomers exist for this molecule?
none
two
four
six
eight
answer
two
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MAKE CONNECTIONS Which chemical group is most likely to be responsible for an organic molecule behaving as a base (see Concept 3.3, p. 53 in your textbook)?
carbonyl
carboxyl
amino
phosphate
hydroxyl
answer
amino
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Which of the following examples best describes a unique functional property of the carboxyl group?
Its compounds may be structural isomers with different properties.
It is polar as a result of the electronegative oxygen atom drawing electrons toward it.
Two carboxyl groups can bond covalently to help stabilize protein structure.
The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate from oxygen reversibly.
It acts as a base.
answer
The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate from oxygen reversibly.
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A pharmaceutical company was forced to recall a pain reliever medication that had been linked to the fatalities of several hundred people. Analysis of the recalled drug revealed the presence of two isomers due to an asymmetrical carbon atom in the drug molecule. What can be hypothesized from this observation?
The isomers are enantiomers, with one having toxic effects on humans.
Isomers involving an asymmetrical carbon are distinguished by the tendency for functional groups to form ionic bonds with the carbon that readily break in solution. The toxic effect of the drug is due to the highly reactive nature of the dissolved functional groups.
The asymmetrical carbon causes the solubility of the two drug isomers to vary significantly, thus having different chemical properties and effects on people who take them.
The two isomers of the drug contain different functional groups and the isomer with the aberrant functional group is connected to the fatalities.
The double bond involving the asymmetrical carbon can generate cis-trans isomers that typically have different chemical properties, thus accounting for the drug's toxic properties.
answer
The isomers are enantiomers, with one having toxic effects on humans.
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Variations in the reactive properties of different organic molecules are most closely associated with _____.
the presence or absence of functional groups
the number of carbon atoms comprising the molecule's skeleton
the orientation of the carbon skeleton, as either ringed or linear
the presence or absence of double bonds
the number of asymmetric carbon atoms present
answer
the presence or absence of functional groups
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Which statement helps most to explain why life is based on carbon compounds?
C-C bonds are as strong as C-O bonds.
C makes strong bonds with O.
Each C atom makes three covalent bonds.
C is very abundant in non-living nature.
All of the above.
answer
C-C bonds are as strong as C-O bonds.
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Which of the following molecules is a weak base?
R—OH
R—SH
R—COOH
R—NH2
None of the listed responses is correct.
answer
R—NH2