Deck 20: Organic and Biological Molecules: the Compounds of Life

Question 1

Aspirin has the chemical structure shown below. Which of the noted functional groups are found in the molecule?

A)only an alcohol
B)only a carboxylic acid
C)both an alcohol and a carboxylic acid
D)only an ester
E)both a carboxylic acid and an ester

Answer 1

both a carboxylic acid and an ester

Question 2

Which functional group is found in the following molecule?

A)aldehyde
B)carboxylic acid
C)ester
D)ether
E)ketone

Answer 2

aldehyde

Question 3

Naproxen has the chemical structure shown below. Which of the noted functional groups are found in the molecule?

A)only an ether
B)both an ester and a carboxylic acid
C)both an ether and a carboxylic acid
D)only an ester
E)both an ether and an ester

Answer 3

both an ether and a carboxylic acid

Question 4

Which structure contains the ketone functional group?

A)
B)
C)
D)
E)

Question 5

Which structure contains the alkyne functional group?

A)
B)
C)
D)
E)

Question 6

Which of these functional groups does not contain a carbonyl group?

A)aldehyde
B)carboxylic acid
C)ester
D)ether
E)ketone

Question 7

Which of the noted functional group(s) is/are found in the following molecule?

A)only a carboxylic acid
B)only an ester
C)only an ether
D)only a ketone
E)both an ether and a ketone

Question 8

Which structure contains the ester functional group?

A)
B)
C)
D)
E)

Question 9

Which functional group is found in the following molecule?

A)aldehyde
B)carboxylic acid
C)ester
D)ether
E)ketone

Question 10

Which structure contains the ester functional group?

A)
B)
C)
D)
E)

Question 11

A subunit of an organic compound that confers particular chemical and physical properties is termed ________

A)a monomer.
B)an oligomer.
C)a functional group.
D)a synthetic unit.
E)an isomer.

Question 12

Fluvalinate is a pesticide used to control mite populations in honeybee colonies. Identify the ether functional group in fluvalinate.

A)I
B)II
C)III
D)IV
E)V

Question 13

Which structure contains the aldehyde functional group?

A)
B)
C)
D)
E)All of the above illustrate the aldehyde functional group.

Question 14

Which structure contains the ketone functional group?

A)
B)
C)
D)
E)All of the above illustrate the ketone functional group.

Question 15

Which of the noted functional group(s) is/are found in the following molecule?

A)only an amide
B)only an ether
C)both a ketone and an ether
D)contains an amine, ether, and a ketone
E)both an ether and an amide

Question 16

Which structure contains the ether functional group?

A)
B)
C)
D)
E)

Question 17

The functional group -COOH is characteristic of ________

A)a carboxylic acid.
B)an amide.
C)an alkane.
D)an alcohol.
E)an ester.

Question 18

Which of these molecules are structural isomers of n-octane (C₈H₁₈)?

A)I, III, and IV
B)II and V
C)only II has 8 carbon atoms in a chain
D)III and IV
E)I, II, III, IV, and V

Question 19

Ranitidine, with a trade name of Zantac, is a drug that inhibits stomach acid production, preventing heartburn and acid indigestion. Identify the amine functional group(s) in ranitidine.

A)I
B)II
C)III
D)IV
E)I and IV

Question 20

Indometacin is a nonsteroidal antiinflammatory drug, often used to treat tendinitis or gout in patients. Identify the carboxylic acid functional group(s) in indometacin.

A)I
B)II
C)III
D)IV
E)III and IV

Question 21

This molecule is ________

A)a lipid.
B)a fatty acid.
C)an amino acid.
D)a nucleic acid.
E)a saccharide.

Question 22

Which of the following are not amino acids?
I.
II.
III.
IV.

A)III and IV
B)I and II
C)I and IV
D)II and III only
E)II and IV only

Question 23

Which of the following is/are amino acids?
I.
II.
III.
IV.

A)III and IV
B)I and II
C)I only
D)II only
E)III only

Question 24

A derivative of glycopyrollate, a medication often administered before a patient's surgery, is shown below. How many chiral centers are there in the molecule?

A)0
B)1
C)2
D)3
E)4

Question 25

Which of the following molecules is/are chiral?

A)I only
B)II only
C)III only
D)I and II
E)II and III

Question 26

Which of the following compounds is an $\alpha$ -amino acid?

A)
B)
C)
D)

Question 27

Consider the 1,2-dichloro derivative of ethylene, in which one of the hydrogen atoms on each of the carbon atoms in ethylene is substituted with a chlorine atom, giving the structural formula CHClCHCl. Does this molecule have geometrical isomers? Remember that ethylene does not.

A)Yes, because the chlorines can be placed on the same or opposite sides of the double bond.
B)Yes, because the chlorines can be placed on either one or both of the carbons.
C)No, because both the formula and bonds are the same in all skeletal structures.
D)No, because the two structures can interconvert through bond rotation.
E)No, because there are less than four atoms bound to each carbon.

Question 28

An $\alpha$ -amino acid is one in which the amine group and the carboxylic acid group are attached to ________

A)different carbon atoms.
B)different nitrogen atoms.
C)the same carbon atom.
D)the first and third carbon of the molecule.
E)neighboring carbon atoms.

Question 29

The human body can synthesize 12 of the 20 amino acids necessary for survival, but the other 8 must be obtained from food. These amino acids are called ________ amino acids.

A)critical
B)essential
C)external
D)vital
E)necessary

Question 30

How many structural isomers (also called constitutional isomers) are there for butene, and why?

A)two, because of resonance
B)two, because of geometrical isomerism and two of the structures can be superimposed
C)two, because the double bond can be in either one of two locations
D)three, because of geometrical isomerism and the double bond can be in different locations
E)three, because of resonance and the double bond can be in different locations

Question 31

An amino acid is composed of ________

A)ammonia and a carboxylic acid group.
B)an amine and a carboxylic acid group.
C)an amine and an alcohol group.
D)an amine and a sulfonic acid group.
E)an amide and a hydrochloric acid group.

Question 32

For each of the bonds in the figure below, identify whether the bond is cis, trans, or neither cis nor trans.

A)I-cis; II-trans; III-cis
B)I-trans; II-cis; III-trans
C)I-neither; II-trans; III-cis
D)I-neither; II-cis; III-trans
E)I-neither; II-cis; III-cis

Question 33

Which statement best describes how these three molecules are related?

A)They are not related, they are different molecules.
B)They are structural isomers.
C)They are stereoisomers.
D)They illustrate cis-trans isomerization.
E)They are the same compound.

Question 34

Which one of the following is not an amino acid?

A)
B)
C)
D)
E)

Question 35

Consider the 1,2-dichloro derivative of ethylene, in which one of the hydrogen atoms on each of the carbon atoms in ethylene is substituted with a chlorine atom, giving the condensed structure CHClCHCl. Which of the following is true?

A)The cis isomer is more polar.
B)The trans isomer is more polar.
C)Neither cis nor trans isomers are polar.
D)Both cis and trans isomers are equally polar.
E)There are no isomers for this molecule.

Question 36

How many chiral centers are there in the following molecule?

A)0
B)1
C)2
D)3
E)4

Question 37

Which one of the following is an example of an amino acid?

A)
B)
C)
D)
E)

Question 38

Does this molecule have both cis and trans isomers?

A)Yes, this is the cis isomer.
B)Yes, this is the trans isomer.
C)No, it has only the cis isomer.
D)No, it has only the trans isomer.
E)No, this molecule does not have cis-trans isomerism.

Question 39

How many chiral centers are there in the following molecule?

A)0
B)1
C)2
D)3
E)4

Question 40

For each of the bonds in the following unsaturated fatty acid shown below, identify whether the bond is cis, trans, or neither cis nor trans.

A)I-cis; II-trans; III-cis
B)I-trans; II-cis; III-trans
C)I-neither; II-trans; III-cis
D)I-cis; II-trans; III-neither
E)I-trans; II-cis; III-neither

Question 41

Aspartame exists as a zwitterion with a ________ amine group and a ________ carboxylic acid group.

A)deprotonated; protonated
B)protonated; deprotonated
C)protonated; protonated
D)deprotonated; deprotonated
E)functionalized; defunctionalized

Question 42

Which one of the following is best associated with proteins?

A)amino acids
B)saccharides
C)hydrocarbon chains
D)phosphate linkages
E)hydrocarbon rings

Question 43

Which statement about amino acid enantiomers is not correct?

A)An enantiomer cannot be superimposed on its mirror image.
B)Enantiomers are examples of stereoisomers.
C)A solution of an enantiomer rotates the plane of polarized light.
D)Enantiomers are designated by the prefixes D and L.
E)All the chiral amino acids in our bodies are mixtures of enantiomers.

Question 44

At a physiological pH of 7.4, amino acids exist as zwitterions. At a very low pH (in an acid solution), both the amine group and the carboxylic acid group on an amino acid are protonated. Which acid group is the stronger acid?

A)(-NH₂)
B)(-NH₃⁺)
C)(-COOH)
D)(-COO^-
E)(-H₃O⁺)

Question 45

Which one of the following molecules is chiral?

A)
B)
C)
D)
E)

Question 46

At a physiological pH of 7.4, amino acids exist as zwitterions because the pK_a of the -NH₃⁺ group is ________ 7.4, and the pK_a of the -COOH group is ________ 7.4.

A)greater than; less than
B)less than; greater than
C)greater than; greater than
D)less than; less than
E)equal to; equal to

Question 47

The molecule drawn below is an example of ________

A)a nucleic acid base.
B)a peptide.
C)a carbohydrate.
D)a fatty acid.
E)an amino acid.

Question 48

At a physiological pH of 7.4, which of the following would be an accurate representation of the structure of the amino acid serine?

A)
B)
C)
D)
E)

Question 49

Which of the following is the correct structure of alanine at its isoelectric point?

A)
B)
C)
D)

Question 50

Which statement is not correct? A chiral molecule ________

A)is an enantiomer.
B)rotates the plane of polarized light.
C)has four different groups bonded to the same carbon atom.
D)has properties different from those of its mirror image.
E)can be superimposed on its mirror image.

Question 51

An oligopeptide consists of up to ________ amino acids that bond together.

A)5
B)20
C)10
D)15
E)50

Question 52

The following reaction produces a peptide. Which statement about this reaction is not correct?

A)The peptide shown is the only product produced by this reaction.
B)This condensation reaction produces a peptide bond.
C)An amide group is formed in this reaction.
D)An amino group reacts with a carboxylic acid group.
E)Two amino acids are linked together by this reaction.

Question 53

Which statement about chirality is not correct?

A)A molecule is chiral if it has a carbon atom bonded to four different groups.
B)A molecule is chiral if it cannot be superimposed on its mirror image.
C)Almost all amino acids are chiral.
D)In an amino acid, the $\alpha$ -carbon is the chiral center.
E)Chiral amino acids each have three enantiomers.

Question 54

Amino acids bond together via ________ bonds.

A)ionic
B)coordinate covalent
C)hydrogen
D)peptide
E)van der Waals

Question 55

Which of the following are not amino acids?

A)I and III
B)II and III
C)I and IV
D)II and III only
E)II and IV only

Question 56

Isomers that cannot be superimposed on their mirror images are called ________

A)geometric isomers.
B)structural isomers.
C)enantiomers.
D)isotopes.
E)constitutional isomers.

Question 57

At a physiological pH of 7.4, amino acids exist as zwitterions. At a very low pH (in an acid solution), both the amine group and the carboxylic acid group on an amino acid are protonated. Therefore, the following must be true: the pK_a of the ________ group is larger than the pK_a of the ________ group.

A)protonated amine; carboxylic acid
B)carboxylic acid; protonated amine
C)amine; carbonate
D)hydronium ion; hydroxyl ion
E)carbonate; amine

Question 58

A peptide bond is the result of a condensation reaction between ________

A)two carboxylic acid groups on different amino acids.
B)an amino group on one amino acid and the carboxylic acid group on another.
C)two amino groups on different amino acids.
D)an amino group and a carboxylic acid group on the same amino acid.
E)an amino group and a carboxylic acid group, producing a zwitterion.

Question 59

Identify the peptide bond in a derivative of aspartame, a popular artificial sweetener with the trade name NutraSweet.

A)I
B)II
C)III
D)IV

Question 60

Which one of the following molecules is chiral?

A)
B)
C)
D)
E)

Question 61

Glucose is to starch as ________

A)pure gold is to 14-karat gold.
B)a link is to a chain.
C)a leaf is to a tree.
D)a trumpet is to a tuba.
E)a tomato is to a potato.

Question 62

Which of the following molecular formulas identifies a monosaccharide?

A)CH₂O
B)C₆H₁₀O₅
C)C₁₂H₂₂O₁₁
D)C₂H₄O₂
E)C₆H₁₂O₆

Question 63

The molecule drawn below is an example of ________

A)a nucleic acid base.
B)an amino acid.
C)a carbohydrate.
D)a fatty acid.
E)a lipid.

Question 64

A carbohydrate has an empirical formula of ________

A)CH₂O.
B)C₆H₁₂O₆.
C)C₁₂H₂₂O₁₁.
D)C₂H₄O₂.
E)C₃H₆O₃.

Question 65

Which of the following is not a monosaccharide?

A)fructose
B)glucose
C)dextrose
D)cellulose
E)( $\beta$ -fructose)

Question 66

Inhibitors can operate by
I.decreasing the concentration of a substrate.
II.binding at the enzyme active site, blocking reaction with substrate.
III.inducing a change in the protein structure by binding at a remote site.
IV.increasing the activation energy for a reaction.

A)I and IV only
B)I and III only
C)II and III only
D)II, III, and IV only
E)All are correct.

Question 67

The $\alpha$ -helix and $\beta$ -pleated sheet are examples of ________

A)primary structure.
B)secondary structure.
C)tertiary structure.
D)arrangement structure.
E)quaternary structure.

Question 68

Which of the following is not a potential function of a protein?

A)signaling molecule
B)transport
C)enzyme catalyst
D)structural unit
E)all of the above are protein functions

Question 69

Which of the following molecular formulas identifies a carbohydrate?

A)CH₂O
B)C₆H₁₂O₆
C)C₁₂H₂₂O₁₁
D)
E)C₁₂H₆O₁₂

Question 70

The ordering of subunits, such as amino acids, in a polymer, is called ________

A)the primary structure.
B)the secondary structure.
C)the tertiary structure.
D)the ordering structure.
E)the quaternary structure.

Question 71

The molecule drawn below is an example of ________

A)a nucleic acid base.
B)an amino acid.
C)a disaccharide.
D)a fatty acid.
E)a lipid.

Question 72

Which one of the following is best associated with carbohydrates?

A)amino acids
B)saccharides
C)hydrocarbon chains
D)phosphate linkages
E)hydrocarbon rings

Question 73

Which of the following is a monosaccharide?

A)sucrose
B)glucose
C)starch
D)cellulose
E)cellobiose

Question 74

Which functional group links amino acids together to form proteins?

A)amide
B)ester
C)ether
D)amine
E)phosphate

Question 75

Which of the following is not a description of the secondary structure of a protein?

A)( $\alpha$ -helix)
B)( $\beta$ -pleated sheets)
C)random coil
D)sequence of amino acids in the protein
E)geometric patterns formed by amino acids

Question 76

Which one of the following is an example of a monosaccharide?

A)
B)
C)
D)

Question 77

A disaccharide has a molecular formula of ________

A)CH₂O.
B)C₆H₁₀O₅.
C)C₁₂H₂₂O₁₁.
D)C₂H₄O₂.
E)C₁₂H₂₄O₁₂.

Question 78

The primary structure of a protein is ________

A)the sequence of amino acids in the protein.
B)the $\alpha$ -helix structure of the protein.
C)the $\beta$ -pleated sheet structure of the protein.
D)a list of the amino acids in the protein along with the number of times each occurs.
E)the arrangement of $\alpha$ -helices and $\beta$ -pleated sheets in the protein.

Question 79

The assembly and interaction of coils and sheets in a polypeptide to produce the overall three-dimensional shape are described by the term ________

A)primary structure.
B)secondary structure.
C)tertiary structure.
D)long-range structure.
E)quaternary structure.

Question 80

Which of the following statements is not true about enzyme catalysis?

A)The reactant in an enzymatic reaction is called a substrate.
B)The lock-and-key model of enzyme catalysis relies on a perfect fit between enzyme and reactant to promote reaction.
C)The active site is the region of the protein that binds the reactant.
D)Inhibitors can bind only at the enzyme-active site to prevent reaction from occurring.
E)The induced fit model assumes that subtle changes mediated by reactant binding in the enzyme-active site lower the barrier for the desired reaction.