Deck 4: Carbon and the Molecular Diversity of Life

Question 1

Stanley Miller's 1953 experiments assumed that early Earth's atmosphere contained

A)hydrogen cyanide, formaldehyde, hydrogen gas, and water vapour.
B)ammonia, methane, hydrogen gas, and water vapour.
C)ammonia, methane, oxygen gas, and water vapour.
D)amino acids, methane, hydrogen cyanide, and water vapour.
E)methane, formaldehyde, ammonia, and carbon dioxide.

Answer 1

B

Question 2

What is the key reason that often only one isomer of a pair of enantiomers is biologically active?

A)The functional groups in isomers may be found on the same or opposite sides of a double bond.
B)Isomers of an organic molecule may have either branched or linear structures.
C)One isomer may take up more volume.
D)One isomer may be more polar than the other.
E)Only one isomer may bind to specific target molecules in an organism.

Answer 2

E

Question 3

Why are hydrocarbons insoluble in water?

A)The majority of their bonds are polar covalent carbon-to-hydrogen linkages.
B)The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
C)They are hydrophilic.
D)They exhibit considerable molecular complexity and diversity.
E)They are lighter than water.

Answer 3

B

Question 4

The experimental approach taken in current biological investigations presumes that

A)simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can only be synthesized by living organisms.
B)a life force ultimately controls the activities of living organisms and this life force cannot be studied by physical or chemical methods.
C)although a life force, or vitalism, exists in living organisms, this life force cannot be studied by physical or chemical methods.
D)living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products.
E)living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena.

Question 5

The element present in all organic molecules is

A)hydrogen.
B)oxygen.
C)carbon.
D)nitrogen.
E)phosphorus.

Question 6

Stanley Miller's 1953 experiments proved that

A)life arose on Earth from simple inorganic molecules.
B)organic molecules can be synthesized abiotically under conditions that may have existed on early Earth.
C)life arose on Earth from simple organic molecules, with energy from lightning and volcanoes.
D)the conditions on early Earth were conducive to the origin of life.
E)the conditions on early Earth were conducive to the abiotic synthesis of organic molecules.

Question 7

Which of the following statements correctly describes cis-trans isomers?

A)They have variations in arrangement around a double bond.
B)They have an asymmetric carbon that makes them mirror images.
C)They have the same chemical properties.
D)They have different molecular formulas.
E)Their atoms and bonds are arranged in different sequences.

Question 8

A carbon atom is most likely to form what kind of bond(s)with other atoms?

A)ionic
B)hydrogen
C)covalent
D)covalent bonds and hydrogen bonds
E)ionic bonds, covalent bonds, and hydrogen bonds

Question 9

What determines whether a carbon atom's covalent bonds to other atoms are in a tetrahedral configuration or a planar configuration?

A)the presence or absence of bonds with oxygen atoms
B)the presence or absence of double bonds between the carbon atom and other atoms
C)the polarity of the covalent bonds between carbon and other atoms
D)the presence or absence of bonds with nitrogen atoms
E)the solvent that the organic molecule is dissolved in

Question 10

Research indicates that ibuprofen,a drug used to relieve inflammation and pain,is a mixture of two enantiomers,that is,molecules that

A)have identical chemical formulas but differ in the branching of their carbon skeletons.
B)are mirror images of one another.
C)exist in either linear chain or ring forms.
D)differ in the location of their double bonds.
E)differ in the arrangement of atoms around their double bonds.

Question 11

Which of the following correctly describes ATP?

A)ATP is hydrophobic.
B)ATP is inorganic.
C)ATP is unable to react with water.
D)ATP has two covalently attached phosphates.
E)ATP is able to store energy for the cell.

Question 12

Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds,a hydrocarbon chain with the same number of carbon atoms,but with one or more double bonds,will

A)be more flexible in structure.
B)be more constrained in structure.
C)be more polar.
D)have more hydrogen atoms.
E)have fewer structurally distinct isomers.

Question 13

When Stanley Miller applied heat and electrical sparks to a mixture of simple inorganic compounds such as methane,hydrogen gas,ammonia,and water vapour,what compounds were produced?

A)mostly amino acids
B)only simple organic compounds such as formaldehyde and cyanide
C)mostly hydrocarbons
D)only simple inorganic compounds
E)both simple organic compounds and more complex organic compounds such as amino acids and hydrocarbons

Question 14

The complexity and variety of organic molecules is due to

A)the chemical versatility of carbon atoms.
B)the variety of rare elements in organic molecules.
C)the fact that they can be synthesized only in living organisms.
D)their interaction with water.
E)their tremendously large sizes.

Question 15

Differences among organisms are caused by

A)large differences in elemental composition from organism to organism.
B)differences in the types and relative amounts of organic molecules synthesized by each organism.
C)differences in the elements that bond with carbon in each organism.
D)differences in the sizes of the organic molecules in each organism.
E)differences in inorganic compounds present in each organism.

Question 16

Organic molecules with only hydrogens and five carbon atoms can have different structures in all of the following ways except

A)by branching of the carbon skeleton.
B)by varying the number of double bonds between carbon atoms.
C)by varying the position of double bonds between carbon atoms.
D)by forming a ring.
E)by forming enantiomers.

Question 17

Which of the following people was the first to synthesize an organic compound,urea,from inorganic starting materials?

A)Stanley Miller
B)Jakob Berzelius
C)Friedrich Wohler
D)Hermann Kolbe
E)August Kekulé

Question 18

How many structural isomers are possible for a substance having the molecular formula C₄H₁₀?

A)1
B)2
C)4
D)3
E)11

Question 19

How many electron pairs does carbon share in order to complete its valence shell?

A)1
B)2
C)3
D)4
E)8

Question 20

A compound contains hydroxyl groups as its predominant functional group.Which of the following statements is true concerning this compound?

A)It lacks an asymmetric carbon, and it is probably a fat or lipid.
B)It should dissolve in water.
C)It should dissolve in a nonpolar solvent.
D)It won't form hydrogen bonds with water.
E)It is hydrophobic.

Question 21

Of the biologically important functional groups listed below,which is not reactive but serves as a tag or marker?

A)hydroxyl
B)carboxyl
C)amino
D)sulfhydryl
E)methyl

Question 22

Hydrocarbons are ________ because most of their bonds are ________ carbon-hydrogen links.

A)hydrophilic; polar
B)hydrophilic; charged
C)hydrophobic; polar
D)hydrophobic; non-polar
E)inorganic; not

Question 23

Which of the following is a false statement concerning amino groups?

A)They are basic in pH.
B)They are found in amino acids.
C)They contain nitrogen.
D)They are nonpolar.
E)They are components of urea.

Question 24

Organic chemistry is the study of molecules containing

A)water.
B)carbon.
C)hydrogen.
D)nitrogen.
E)oxygen.

Question 25

Which of the pairs of molecular structures shown below do not depict enantiomers (enantiomeric forms)of the same molecule?

A)
B)
C)
D)
E)

Question 26

Testosterone and estradiol are male and female sex hormones,respectively,in many vertebrates.In what way(s)do these molecules differ from each other?

A)Testosterone and estradiol are structural isomers but have the same molecular formula.
B)Testosterone and estradiol are cis-trans isomers but have the same molecular formula.
C)Testosterone and estradiol have different functional groups attached to the same carbon skeleton.
D)Testosterone and estradiol have distinctly different chemical structures, with one including four fused rings of carbon atoms, while the other has three rings.
E)Testosterone and estradiol are enantiomers of the same organic molecule.

Question 27

The two molecules shown in the figure above are best described as

A)optical isomers.
B)enantiomers.
C)structural isomers.
D)cis-trans isomers.
E)chain length isomers.

Question 28

What is an important source of the molecular complexity and diversity of living matter?

A)The unique properties of water.
B)The variation in carbon skeletons.
C)The non-polar nature of hydrocarbons.
D)The diversity of elements on Earth.
E)Evolution.

Question 29

Which of the following people used this apparatus to study the formation of organic compounds?

A)Stanley Miller
B)Jakob Berzelius
C)Friedrich Wohler
D)Hermann Kolbe
E)August Kekulé

Question 30

Amino acids are acids because they always possess which functional group?

A)amino
B)carbonyl
C)carboxyl
D)phosphate
E)hydroxyl

Question 31

The two molecules shown in the figure above are best described as

A)enantiomers.
B)radioactive isotopes.
C)structural isomers.
D)nonisotopic isomers.
E)cis-trans isomers.

Question 32

Use the following figure to answer the questions below.

The figure above shows the structures of glucose and fructose.These two molecules differ in the

A)number of carbon, hydrogen, and oxygen atoms.
B)types of carbon, hydrogen, and oxygen atoms.
C)arrangement of carbon, hydrogen, and oxygen atoms.
D)number of oxygen atoms joined to carbon atoms by double covalent bonds.
E)number of carbon, hydrogen, and oxygen atoms; the types of carbon, hydrogen, and oxygen atoms; and the arrangement of carbon, hydrogen, and oxygen atoms.

Question 33

A carbon skeleton is covalently bonded to both an amino group and a carboxyl group.When placed in water,it

A)would function only as an acid because of the carboxyl group.
B)would function only as a base because of the amino group.
C)would function as neither an acid nor a base.
D)would function as both an acid and a base.
E)is impossible to determine how it would function.

Question 34

Of the biologically important functional groups listed below,which acts as a base?

A)hydroxyl
B)carboxyl
C)amino
D)sulfhydryl
E)methyl

Question 35

Three or four of the following illustrations depict different structural isomers of the organic compound with molecular formula C₆H₁₄.For clarity,only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.Which one,if any,is not a structural isomer of this compound?

A)
B)
C)
D)
E)Each of the illustrations in the other answer choices depicts a structural isomer of the compound with molecular formula C₆H₁₄.

Question 36

Which functional groups can act as acids?

A)amino and sulfhydryl
B)carbonyl and carboxyl
C)carboxyl and phosphate
D)hydroxyl and aldehyde
E)ketone and amino

Question 37

Which of the pairs of molecular structures shown below depict enantiomers (enantiomeric forms)of the same molecule?

A)
B)
C)
D)
E)

Question 38

Which two functional groups are always found in amino acids?

A)ketone and methyl
B)carbonyl and amino
C)carboxyl and amino
D)amino and sulfhydryl
E)hydroxyl and carboxyl

Question 39

Of the biologically important functional groups listed below,which is hydrophobic and can make cross-bridges?

A)hydroxyl
B)carboxyl
C)amino
D)sulfhydryl
E)methyl

Question 40

Use the following figure to answer the questions below.

The figure above shows the structures of glucose and fructose.These two molecules are

A)geometric isotopes.
B)enantiomers.
C)cis-trans isomers.
D)structural isomers.
E)nonisotopic isomers.

Question 41

Use the following figure to answer the questions below.

In which of the structures illustrated above are the atoms bonded by ionic bonds?

A)A
B)B
C)C
D)C, D, and E only
E)none of the structures

Question 42

Use the following figure to answer the questions below.

Which of the groups above is an acidic functional group that can dissociate and release H⁺ into a solution?

A)A
B)B
C)C
D)D
E)E

Question 43

Use the following figure to answer the questions below.

Which functional group(s)shown above is (are)present in all amino acids?

A)A and B
B)B and D
C)C only
D)D only
E)C and D

Question 44

Use the following figure to answer the questions below.

Which molecule(s)shown above is (are)ionized in aqueous solution at pH 7?

A)A
B)B and D
C)D and E
D)D
E)E

Question 45

Use the following figure to answer the questions below.

Which molecule shown above has a carbonyl functional group in the form of an aldehyde?

A)A
B)B
C)C
D)D
E)E

Question 46

Use the following figure to answer the questions below.

Which functional group shown above is characteristic of alcohols?

A)A
B)B
C)C
D)D
E)E

Question 47

Use the following figure to answer the questions below.

Which of the structures illustrated above cannot form hydrogen bonds with water molecules?

A)A
B)B
C)C
D)D
E)E

Question 48

Use the following figure to answer the questions below.

Which of the structures illustrated above is an impossible covalently bonded molecule?

A)A
B)B
C)C
D)D
E)E

Question 49

Use the following figure to answer the questions below.

Which molecules shown above contain a carbonyl group?

A)A and B
B)B and C
C)B, C, and D
D)D and E
E)E and A

Question 50

L-dopa and D-dopa,shown below,are an example of a pharmaceutical drug that occurs as enantiomers,or molecules that

A)have identical three-dimensional shapes.
B)are mirror images of one another.
C)are structural isomers.
D)are mirror images of one another and are likely to have the same biological activity.
E)are cis-trans isomers.

Question 51

Use the following figure to answer the questions below.

Which of the groups above is a carboxyl functional group?

A)A
B)B
C)C
D)D
E)E

Question 52

Use the following figure to answer the questions below.

Which of the groups above is a basic functional group that can accept H⁺ and become positively charged?

A)A
B)B
C)C
D)D
E)E

Question 53

Use the following figure to answer the questions below.

Which of the structures illustrated above contain(s)a carbonyl functional group?

A)A
B)C and D
C)C
D)D
E)C and E

Question 54

Use the following figure to answer the questions below.

Which of the groups shown above is a carbonyl functional group?

A)A
B)B
C)C
D)D
E)E

Question 55

Use the following figure to answer the questions below.

Which molecule shown above would have a positive charge in aqueous solution at pH 7?

A)A
B)B
C)C
D)D
E)E

Question 56

What is the name of the functional group shown in the figure above?

A)carbonyl
B)ketone
C)aldehyde
D)carboxyl
E)hydroxyl

Question 57

Use the following figure to answer the questions below.

Which of the groups shown above is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules?

A)A
B)B
C)C
D)D
E)E

Question 58

Use the following figure to answer the questions below.

Which molecule shown above has a carbonyl functional group in the form of a ketone?

A)A
B)B
C)C
D)D
E)E

Question 59

Which pair of molecules shown below are not enantiomers of a single molecule?

A)
B)
C)
D)
E)

Question 60

Use the following figure to answer the questions below.

Which molecule shown above contains a carboxyl group?

A)A
B)B
C)C
D)D
E)E

Question 61

Answer the following questions based on the figure below.

Which action could produce a carbonyl group?

A)the replacement of the -OH of a carboxyl group with hydrogen
B)the addition of a thiol to a hydroxyl
C)the addition of a hydroxyl to a phosphate
D)the replacement of the nitrogen of an amine with oxygen
E)the addition of a sulfhydryl to a carboxyl

Question 62

Answer the following questions based on the figure below.

Identify the asymmetric carbon in this molecule.

A)A
B)B
C)C
D)D
E)E

Question 63

Which of the following hydrocarbons has a double bond in its carbon skeleton?

A)C₃H₈
B)C₂H₆
C)CH₄
D)C₂H₄
E)C₂H₂

Question 64

Use the following figure to answer the questions below.

A chemist wishes to make an organic molecule less acidic.Which of the following functional groups should be added to the molecule in order to do so?

A)carboxyl
B)sulfhydryl
C)hydroxyl
D)amino
E)phosphate

Question 65

Which functional group is not present in this molecule?

A)carboxyl
B)sulfhydryl
C)hydroxyl
D)amino

Question 66

Use the following figure to answer the questions below.

Which molecule shown above can form a dimer linked by a covalent bond?

A)A
B)B
C)C
D)D
E)E

Question 67

Why is carbon so important in biology?

A)It is a common element on Earth.
B)It has very little electronegativity, making it a good electron donor.
C)It bonds to only a few other elements.
D)It can form a variety of carbon skeletons and host functional groups.
E)It can be part of either hydrophobic or hydrophilic molecules.

Question 68

Use the following figure to answer the questions below.

Which molecule shown above is a thiol?

A)A
B)B
C)C
D)D
E)E

Question 69

Use the following figure to answer the questions below.

Which molecule shown above can increase the concentration of hydrogen ions in a solution and is therefore an organic acid?

A)A
B)B
C)C
D)D
E)E

Question 70

Use the following figure to answer the questions below.

Which molecules shown above will form hydrogen bonds with water?

A)Only D will form hydrogen bonds with water.
B)All of these molecules will form hydrogen bonds with water.
C)None of these molecules will form hydrogen bonds with water.
D)All of these molecules except B will form hydrogen bonds with water.
E)Only C, D, and E will form hydrogen bonds with water.

Question 71

Choose the term that correctly describes the relationship between these two sugar molecules:

A)structural isomers
B)cis-trans isomers
C)enantiomers
D)isotopes

Question 72

Use the following figure to answer the questions below.

Which molecule shown above can function as a base?

A)A
B)B
C)C
D)D
E)E

Question 73

Which chemical group is most likely to be responsible for an organic molecule behaving as a base?

A)hydroxyl
B)carbonyl
C)carboxyl
D)amino
E)phosphate

Question 74

Organic chemistry is currently defined as

A)the study of compounds made only by living cells.
B)the study of carbon compounds.
C)the study of vital forces.
D)the study of natural (as opposed to synthetic)compounds.
E)the study of hydrocarbons.

Question 75

Answer the following questions based on the figure below.

Which of the following is true of carbon?

A)It forms only polar molecules.
B)It can form a maximum of three covalent bonds with other elements.
C)It is highly electronegative.
D)It can form both polar and nonpolar bonds.
E)It can form ionic bonds.

Question 76

Use the following figure to answer the questions below.

Which molecule shown above contains a functional group that cells use to transfer energy between organic molecules?

A)A
B)B
C)C
D)D
E)E

Question 77

Use the following information to answer the questions below.
You are investigating the differences between three organic compounds.They all have the same carbon skeleton but have differences in their functional groups.
The second molecule is hydrophobic and has acidic properties.It most likely has

A)no functional groups attached and is a hydrocarbon.
B)at least one carboxyl group.
C)at least one amino group.
D)at least one carbonyl group.
E)phosphates.

Question 78

Use the following information to answer the questions below.
You are investigating the differences between three organic compounds.They all have the same carbon skeleton but have differences in their functional groups.
You test for hydrophobicity and observe that one molecule type is extremely hydrophobic.Which of the following is the best possible conclusion?

A)It has no functional groups attached and is a hydrocarbon.
B)It contains at least one carboxyl group.
C)It contains an amino group.
D)It has at least one hydroxyl group.
E)It contains phosphates.

Question 79

Use the following information to answer the questions below.
You are investigating the differences between three organic compounds.They all have the same carbon skeleton but have differences in their functional groups.
The third molecule displays both acidic and basic properties.It most likely has

A)at least one carboxyl group.
B)at least one amino group.
C)at least one hydroxyl group.
D)both an amino and a carboxyl group.
E)both an hydroxyl and a carboxyl group.

Question 80

Use the following figure to answer the questions below.

Which molecule shown above contains an amino functional group,but is not an amino acid?

A)A
B)B
C)C
D)D
E)E