Deck 4: Carbon: the Basis of Molecular Diversity

Question 1

Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, which of the following statements best describe a hydrocarbon chain with the same number of carbon atoms but with one or more double bonds?

A) It will be more flexible in structure.
B) It will be more constrained in structure.
C) It will be more polar.
D) It will contain more hydrogen atoms.

Answer 1

B

Question 2

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; what are enantiomers?

A) Molecules that have identical chemical formulas but differ in the branching of their carbon skeletons.
B) Molecules that are mirror images of each other.
C) Molecules that differ in the location of their double bonds.
D) Molecules that differ in the arrangement of atoms around their double bonds.

Answer 2

B

Question 3

Miller's classic experiment demonstrated that a discharge of sparks through a mixture of gases could result in the formation of a large variety of organic compounds. Miller did not use which one of the following gases in his experiment?

A) methane
B) oxygen
C) water
D) ammonia

Answer 3

B

Question 4

Which of the following factors determines whether a carbon atom's covalent bonds with other atoms are in a tetrahedral configuration or a planar configuration?

A) temperature of the solvent
B) double bonds between the carbon atom and other atoms
C) polarity of the covalent bonds
D) solvent in which the organic molecule is dissolved

Question 5

Thalidomide was sold as "racemic mixture" to pregnant women to treat morning sickness during pregnancy but the drug was found to harm fetus in the womb. It was banned in 1962. Which of the following reasons is the best explanation of the harmful effects of the drug?

A) Racemic mixture of any compound is always toxic and should be avoided.
B) (+)(R)-thalidomide is a sedative, but (-)(S)-thalidomide is a teratogen (a drug that is toxic in nature).
C) Thalidomide is not isomeric in nature thus causes adverse events.
D) Thalidomide was under dosed.

Question 6

Which of the following accurately describes a characteristic of isomers?

A) Isomers differ in both physical and chemical properties.
B) Isomers have same molecular formula.
C) Isomers are not structurally different.
D) Geometric and Optical isomerism are two types of stereoisomerism.

Question 7

Which statement is true about the following molecule?

A) It is a cis isomer.
B) It is a trans isomer.
C) It is cis in its vapor form and trans in its fluid form.
D) It is not an isomer.

Question 8

Which of the following characteristics is responsible for the complexity and variety of organic molecules?

A) the chemical versatility of carbon atoms
B) the variety of rare elements in organic molecules
C) the diverse bonding patterns of nitrogen
D) their interaction with water

Question 9

Which of the following statements is correct for organic molecules with only hydrogens and five carbon atoms?

A) only a linear carbon skeleton is possible for the molecule
B) only carbon number 1 and 2 can form a double bond between them
C) different positions of double bonds between carbon atoms is not possible
D) the molecule cannot have enantiomers

Question 10

Which of the following characteristics of an atom determines the number and kind of bonds it can form?

A) its atomic number
B) the number of particles in its valence shell
C) its atomic mass
D) the number of particles in its nucleus

Question 11

Which of the following molecules has the fewest characteristics of an organic molecule?

A) water
B) methane
C) keratin-fibrous protein forming the main structure of hair
D) hemoglobin-iron-containing oxygen transport metalloprotein

Question 12

Which of the following unique feature of carbon allows it to support life on Earth?

A) Carbon is hydrophobic in nature.
B) Carbon is the most abundant element on earth.
C) Carbon can form a variety of bonds in nature.
D) Carbon is the most electronegative element in the periodic table.

Question 13

How many electrons must one carbon atom share with other atom or atoms to complete its valence shell?

A) two
B) three
C) four
D) eight

Question 14

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.

Question 15

Differences in which of the following chemical characteristics are responsible for the uniqueness of individuals organisms?

A) elemental composition from organism to organism
B) types and relative amounts of organic molecules synthesized by each organism
C) sizes of the organic molecules in each organism
D) types of inorganic compounds present in each organism

Question 16

The maximum number of hydrogen atoms in an alkane with six carbons is ________.

A) 6
B) 10
C) 12
D) 14

Question 17

The results from Stanley Miller's 1953 experiments can best be used to support which of the following hypotheses?

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

Question 18

Which of the following explains why the valency of carbon is 4 even though it has 6 electrons?

A) donates its 2 electrons to another atom
B) shares its 2 electrons and bonds with another atom
C) has 4 electrons in its first shell and 2 in the second shell
D) has 2 electrons in its first shell and 4 in the second shell

Question 19

Which of the following structures is a correct representation of an alcohol?

A)

B)

C)

D)

Question 20

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

A) ionic
B) hydrogen
C) covalent
D) carbon is an inert element

Question 21

Use the figures to answer the question. Which functional group shown in the figure can accept protons and raise the pH of the surrounding solution?

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

Question 22

Use the figures to answer the following question. Which molecule shown has at least one carbon atom attached to three different chemical groups?

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

Question 23

Use the following figure to answer the question. The two molecules shown in the figures are best described as ________.

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

Question 24

Use the figures to answer the question. Which of the functional groups shown in the figure is present in hexanol but not in hexane?

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

Question 25

Which two functional groups are always found in amino acids?

A) carbonyl and amino groups
B) carboxyl and amino groups
C) amino and sulfhydryl groups
D) hydroxyl and carboxyl groups

Question 26

A compound contains hydroxyl groups as its predominant functional group. Which of the following properties of the molecule can be predicted with the information provided?

A) It lacks an asymmetric carbon and is probably a fat or lipid.
B) It should dissolve in water.
C) It should dissolve in a nonpolar solvent.
D) It will not form hydrogen bonds with water.

Question 27

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

A)

B)

C)

D)

Question 28

Which of the following functional groups is hydrophobic in nature?

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

Question 29

Use the figures to answer the following question. Which molecule shown has a carbonyl functional group in the form of a ketone?

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

Question 30

Which of the following functional groups gives amino acids their acidic character?

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

Question 31

Which of the following functional groups is unreactive but when added to bases of DNA can alter gene expression?

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

Question 32

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In which of the following ways do these molecules differ from each other?

A) They are structural isomers but have the same molecular formula.
B) They are cis-trans isomers but have the same molecular formula.
C) They have different functional groups attached to the same carbon skeleton.
D) They are enantiomers of the same organic molecule.

Question 33

What is the relationship between the following two molecules?

A) They are enantiomers.
B) They are not isomers.
C) They are geometrical isomers.
D) They are the same molecule.

Question 34

Use the following figure to answer the following question. The figure shows the structures of glucose and fructose. Which of the following describes a difference between the two molecules?

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

Question 35

Which of the following identifies the chemical relationship between glucose and fructose?

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

Question 36

Use the figures to answer the following question. Which molecule shown can increase the concentration of hydrogen ions in a solution and is therefore an organic acid?

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

Question 37

Which of the following functional groups is present in acetic acid?

A) hydroxyl group
B) sulfhydryl group
C) carbonyl group
D) carboxyl group

Question 38

Which of the following illustrations is not a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.

A)

B)

C)

D)

Question 39

Use the figures to answer the following question. Which molecule(s) shown is (are) ionized in a cell?

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

Question 40

Which of the following compounds is found in vinegar?

A) nitric acid
B) acetic acid
C) amino acid
D) propionic acid

Question 41

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

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

Question 42

Which chemical change will convert ADP to ATP?

A) by adding energy and a phosphate
B) by adding two phosphates
C) by removing energy and a phosphate
D) by adding a phosphate, energy and oxygen

Question 43

Hydrolysis of ADP produces which of the following products?

A) AMP + Pi + energy
B) ATP + Pi
C) Pi + Pi + water
D) ATP + energy

Question 44

ATP is necessary for life because ________.

A) it tastes good
B) it is soluble in water
C) it speeds up the biological processes
D) it is the principle energy carrying molecule in a cell

Question 45

Use the figures to answer the following question. Which molecule shown can be a result of mercaptoethanol reduction of a disulfide bridge?

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

Question 46

Use the figures to answer the question. Which molecule shown above contains a functional group that is a part of the principal molecule that stores and transfers energy in cells?

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

Question 47

Which of the following statements about ADP/ATP is true?

A) ADP contains more energy than ATP.
B) Following hydrolysis, ATP can release one phosphate, whereas ADP cannot.
C) ADP can have two positive charges.
D) ATP can have four negative charges.

Question 48

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 natural (as opposed to synthetic) compounds
D) the study of hydrocarbons

Question 49

Which functional group is present in this molecule?

A) sulfhydryl
B) carboxyl
C) methyl
D) phosphate

Question 50

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

Question 51

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 52

Visualize the structural formula of each of the following hydrocarbons. Which hydrocarbon has a double bond in its carbon skeleton?

A) C₃H₈
B) C₂H₆
C) C₂H₄
D) C₂H₂