Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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What is the name of the negatively charged particles shown in this model of an
atom?  a. | electrons | b. | protons | c. | neutrons | d. | prions |
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2.
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Which of the following statements is true of the substance produced in the
simple chemical reaction depicted in Figure 2.2?  a. | It is in a different physical state than the original substances. | b. | It is identical to
the original substances. | c. | It is a compound, just like the original
substances. | d. | It contains more atoms than the original substances. |
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3.
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An ion is formed when an atom gains or loses
a. | protons. | b. | neutrons. | c. | bonds. | d. | electrons. |
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4.
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Atoms connected by covalent bonds share
a. | pairs of electrons. | b. | ionic compounds. | c. | carbon and
oxygen. | d. | hydrogen ions. |
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5.
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Hydrogen bonds can form between regions of polar molecules that are
a. | nonpolar. | b. | negatively charged. | c. | oppositely
charged. | d. | uncharged (neutral). |
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6.
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The attraction among molecules of different substances is called
a. | cohesion. | b. | adhesion. | c. | specific
heat. | d. | surface tension. |
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7.
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Which of the following phrases best describes a solvent?
a. | has a high concentration of solutes | b. | can be dissolved by the
solute | c. | present in a greater concentration than solutes | d. | usually a sugar or a
protein |
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8.
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A solution with a high concentration of H ions
a. | shows a pH of 7. | b. | kills all organisms. | c. | has a high
pH. | d. | is very acidic. |
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9.
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Carbon is unique due to the carbon atom's
a. | bonding properties. | b. | six outer unpaired
electrons. | c. | ionic compounds. | d. | hydrogen bonding
strength. |
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10.
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Which category of carbon-based molecules includes sugars and starches?
a. | unsaturated fatty acids | b. | phospholipids | c. | proteins | d. | carbohydrates |
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11.
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Fats, oils, and cholesterol are all types of
a. | cell membranes. | b. | hormones. | c. | lipids. | d. | fatty acids. |
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12.
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Proteins are composed of which molecules?
a. | amino acids | b. | fatty acids | c. | monosaccharides | d. | nucleic acids |
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13.
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DNA and RNA are two types of
a. | proteins. | b. | nucleic acids. | c. | lipids. | d. | carbohydrates. |
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14.
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Chemical reactions change substances into different substances by
a. | conserving matter between the substances. | b. | breaking and forming
chemical bonds. | c. | strengthening electrical charges of substances. | d. | changing a solvent
into a solute. |
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15.
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Identify the reactants in the following chemical reaction: 6HO + 6CO  CHO + 6O
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16.
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What is the term for the amount of energy that needs to be added for a chemical
reaction to start?
a. | chemical energy | b. | activation energy | c. | bond
energy | d. | reactant energy |
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17.
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Which phrase best describes an exothermic chemical reaction?
a. | does not absorb any energy | b. | forms products with higher bond energy than
reactants | c. | is in a state of equilibrium | d. | releases more energy than it
absorbs |
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18.
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Which phrase best describes the effect of a catalyst on a chemical
reaction?
a. | increases the temperature | b. | increases the volume of
reactants | c. | decreases the reaction rate | d. | decreases the activation
energy |
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19.
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Enzymes affect chemical reactions in living organisms by
a. | changing the direction of a reaction. | b. | breaking down molecules into
starch. | c. | increasing the temperature range. | d. | weakening bonds in
reactants. |
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20.
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The specific reactants that an enzyme acts on are called
a. | catalysts | b. | proteins. | c. | substrates. | d. | amino acids. |
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21.
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Changes in temperature and pH can decrease an enzyme's activity by
breaking
a. | hydrogen bonds | b. | peptide bonds | c. | amino
acids | d. | sulfur-sulfur bonds |
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22.
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The smallest basic unit of matter is the
a. | molecule. | b. | atom. | c. | compound. | d. | cell. |
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23.
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Which of the following is formed when an atom gains or loses electrons?
a. | element | b. | compound | c. | molecule | d. | ion |
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24.
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Atoms in molecules share pairs of electrons when they make
a. | covalent bonds. | b. | ionic bonds. | c. | hydrogen
bonds. | d. | polymers. |
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25.
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What gives water many properties that are important to living things?
a. | temperature | b. | hydrogen bonds | c. | density | d. | specific heat |
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26.
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Which of the following solutions has the highest H ion concentration?
a. | a solution with a pH of 1 | b. | a solution with a pH of 4 | c. | a solution with a pH
of 7 | d. | a solution with a pH of 10 |
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27.
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What is unique about carbon?
a. | bonding properties | b. | ability to bond with oxygen | c. | properties as a
reactant | d. | properties as an enzyme |
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28.
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The four main types of carbon-based molecules in organisms are carbohydrates,
lipids, nucleic acids, and
a. | starches. | b. | fatty acids. | c. | monosaccharides. | d. | proteins. |
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29.
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Both animal fats and plant oils are made up of glycerol and
a. | phospholipids. | b. | fatty acids. | c. | polar
molecules. | d. | saturated fats. |
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30.
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The activation energy needed for a chemical reaction is decreased by a
a. | catalyst. | b. | reactant. | c. | product. | d. | substrate. |
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31.
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In the lock-and-key model of enzyme function shown in Figure 2.2, what is
happening in step 2?  a. | The catalyzed reaction is releasing a product. | b. | The active sites are
restructuring the enzyme. | c. | The enzyme is causing new bonds to form between
the substrates. | d. | The substrates are beginning to bind to the enzyme. |
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