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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or
answers the question.
1) The simplest chemical units of matter are
1) _______
A) molecules.
B) atoms.
C) electrons.
D) protons.
E) neutrons.
2) Which of the following is the largest in size?
A) a proton
B) an electron
C) a neutron
D) a molecule
E) an atom
2) _______
3) Isotopes of an element differ in the number of
A) electron clouds.
B) electrons in the nucleus.
C) protons in the nucleus.
D) electrons in energy shells.
E) neutrons in the nucleus.
3) _______
4) The atomic number represents the number of
A) electrons in an ion.
B) protons and neutrons.
C) neutrons in an atom.
D) protons in an atom.
E) neutrons and electrons.
4) _______
5) All atoms with the same atomic number are grouped into
A) compounds.
B) elements.
C) cells.
D) isotopes.
E) molecules.
5) _______
6) The mass number of an atom indicates the number of
A) protons and neutrons in the nucleus.
B) protons in the nucleus.
C) electrons in the outer shells.
D) protons and electrons in an atom.
E) neutrons in the nucleus.
6) _______
7) Radioisotopes have unstable
A) electron clouds.
B) isotopes.
C) nuclei.
D) ions.
E) protons.
7) _______
8) The chemical behavior of an atom is determined by
A) the number of neutrons.
B) the mass of the atom.
C) the size of the atom.
D) the number of protons.
E) the number and arrangement of electrons.
8) _______
9) Ions with a positive charge are called
A) isotopes.
B) cations.
C) anions.
D) polyatomic ions.
E) radicals.
9) _______
10) In living cells, the weakest bond between two or more atoms is the
________ bond.
A) nonpolar
B) covalent
C) hydrogen
D) ionic
E) polar
10) ______
11) Ionic bonds are formed when
A) electrons are completely transferred from one atom to another.
B) two or more atoms lose electrons at the same time.
C) a pair of electrons is shared unequally by two atoms.
D) hydrogen forms bonds with negatively charged atoms in the same
or different molecule.
E) atoms share electrons.
11) ______
12) In a molecule of nitrogen, three pairs of electrons are shared by two
nitrogen atoms. The type of bond that is formed would be an example of
a(n)
A) double covalent bond.
B) triple covalent bond.
C) single covalent bond.
D) hydrogen bond.
E) polar covalent bond.
12) ______
13) If a pair of electrons is unequally shared between two atoms, a(n)
________ occurs.
A) double covalent bond
B) hydrogen bond
C) triple covalent bond
D) single covalent bond
E) polar covalent bond
13) ______
14) Elements that have atoms with full outer shells of electrons
A) will form many compounds.
B) will normally form anions.
C) are inert.
D) frequently form hydrogen bonds.
14) ______
E) will normally form cations.
15) Which one of the following statements is not correct about the reaction
H2 + Cl2 → 2 HCl?
A)
B)
C)
D)
E)
15) ______
One molecule of hydrogen contains 2 atoms.
Two molecules of HCl are formed in the reaction.
HCl is the product.
This reaction is an example of a decomposition reaction.
H2 and Cl2 are the reactants.
16) AB → A + B is to decomposition as A + B → AB is to
A) metabolism.
B) synthesis.
C) exchange.
D) combustion.
E) replacement.
16) ______
17) The reaction N2 + 3 H2 → 2 NH3 is an example of a(n)
17) ______
A)
B)
C)
D)
E)
decomposition reaction.
exchange reaction.
synthesis reaction.
metabolic reaction.
enzyme reaction.
18) The reaction A + B → AB + energy is an example of a(n)
A) endergonic reaction.
B) exergonic reaction.
C) equilibrium reaction.
D) exchange reaction.
E) decomposition reaction.
18) ______
19) Chemical reactions that require an input of energy, such as heat, are said
to be
A) exergonic.
B) endergonic.
C) at equilibrium.
D) activated.
E) neutral.
19) ______
20) All of the following are true concerning enzymes, except that they
A) function as biological catalysts.
B) lower the activation energy required for a reaction.
C) become a part of the reaction's product.
D) are proteins.
E) affect only the rate of a chemical reaction.
20) ______
21) Substrate molecules bind to enzymes at the ________ sites.
A) active
B) carboxyl group
C) reactant
D) amino group
E) neutral zone
21) ______
22) All of the compounds that can be synthesized or broken down by
chemical reactions inside the body are called
A) nutrients.
B) enzymes.
C) metabolites.
D) organic compounds.
E) inorganic compounds.
22) ______
23) Each of the following is an example of an inorganic compound, except
A) acids.
B) bases.
C) glucose.
D) salts.
E) water.
23) ______
24) Which of the following statements about water is not correct?
A) contains hydrogen bonds
B) is composed of polar molecules
C) has a relatively low heat capacity
D) can be considered a "universal solvent"
E) is responsible for about 2/3 of the mass of the human body
24) ______
25) During ionization, water molecules disrupt the ionic bonds of a solute
and a mixture of ions is produced. These ions are called
A) anti-ions.
B) dissociates.
C) electrolytes.
D) anions.
E) cations.
25) ______
26) Oppositely charged ions in solution are prevented from combining by
A) the high heat capacity of water.
B) radicals.
C) hydration spheres.
D) hydrogen bonding.
E) water's nonpolar nature.
26) ______
27) A solution containing equal numbers of hydrogen ions and hydroxide
ions is
A) ionated.
B) acidic.
C) basic.
D) neutral.
E) alkaline.
27) ______
28) Which of the following substances would be least acidic?
A) white wine, pH = 3
B) tomato juice, pH = 4
C) urine, pH = 6
D) stomach secretions, pH = 1
E) lemon juice, pH = 2
28) ______
29) If a substance has a pH that is greater than 7, it is
A) alkaline.
B) acidic.
C) a salt.
D) a buffer.
E) neutral.
29) ______
30) An important buffer in body fluids is
A) H2O.
30) ______
B) NaOH.
C) NaHCO3.
D) NaCl.
E) HCl.
31) In the body, inorganic compounds
A) can make up proteins.
B) are important nutrients.
C) are structural components of cells.
D) can serve as buffers.
E) both A and D
31) ______
32) Inorganic compounds that are soluble and whose ions will conduct an
electrical current are called
A) covalent bonds.
B) polar covalent molecules.
C) hydrophobic.
D) hydration spheres.
E) electrolytes.
32) ______
33) Carbohydrate molecules
A) contain the genetic information found in cells.
B) are the body's most readily available source of energy.
C) form the regulatory molecules known as enzymes.
D) are composed of C, H, O, and N atoms.
E) are integral molecules of the cell membrane.
33) ______
34) The most important metabolic fuel molecule in the body is
A) sucrose.
B) glucose.
C) protein.
D) vitamins.
E) starch.
34) ______
35) Molecules that have the same molecular formula but different structural
formulas are called
A) isotopes.
B) isomers.
C) isozymes.
D) isomonomers.
E) isotypes.
35) ______
36) A polysaccharide that is formed in liver and muscle cells to store
glucose is
A) cellulose.
B) glycogen.
C) sucrose.
D) fructose.
E) starch.
36) ______
37) The group of organic compounds containing carbon, hydrogen, and
oxygen in a near 1:2:1 ratio is defined as a
A) nucleic acid.
B) lipid.
C) protein.
D) carbohydrate.
E) both C and D
37) ______
38) Lipids
A) form essential structural components of cells.
B) help to maintain body temperature.
C) provide roughly twice the energy as carbohydrates.
D) all of the above
E) B and C only
38) ______
39) A fatty acid that contains three double covalent bonds in its carbon
chain is said to be
A) monounsaturated.
B) saturated.
C) carboxylated.
D) polyunsaturated.
E) hydrogenated.
39) ______
40) Most of the fat found in the human body is in the form of
A) phospholipids.
B) triglycerides.
C) steroids.
D) monoglycerides.
E) prostaglandins.
40) ______
41) A type of lipid that is produced by nearly every tissue in the body and
that acts as a local regulator of metabolism are the
A) phospholipids.
B) prostaglandins.
C) glycolipids.
D) steroids.
E) monoglycerides.
41) ______
42) Cholesterol, phospholipids, and glycolipids are examples of
A) prostaglandins.
B) structural lipids.
C) dietary fats.
D) lipid drugs.
E) steroids.
42) ______
43) You would expect a peptide bond to link
A) a cholesterol molecule and a fatty acid molecule.
B) two amino acids.
C) two simple sugars.
D) a fatty acid and a glycerol molecule.
E) two nucleotides.
43) ______
44) Each amino acid differs from another in the
A) number of peptide bonds in the molecule.
B) size of the amino group.
C) number of central carbon atoms.
D) number of carboxyl groups.
E) nature of the R group.
44) ______
45) In proteins the alpha-helix and pleated sheet are examples of a ________
structure of a protein.
A) quaternary
B) secondary
C) primary
D) tertiary
E) pentanary
45) ______
46) Proteins have very complex shapes. Interactions between globular or
fibrous polypeptide chains result in which type of structure?
A) quaternary
B) secondary
C) primary
D) pentagonal
E) tertiary
46) ______
47) Glycoproteins and proteoglycans are combinations of proteins and
A) carbohydrates.
B) fatty acids.
C) nucleic acids.
D) lipids.
E) none of the above
47) ______
48) Molecules that store and process genetic information are the
A) carbohydrates.
B) steroids.
C) proteins.
D) nucleic acids.
E) lipids.
48) ______
49) Nucleic acids are composed of units called
A) pyrimidines.
B) fatty acids.
C) amino acids.
D) purines.
E) nucleotides.
49) ______
50) A nucleotide consists of
A) a five-carbon sugar and a nitrogenous base.
B) a five-carbon sugar, a nitrogenous base, and a phosphate group.
C) a phosphate group and a nitrogenous base.
D) a five-carbon sugar and an amino acid.
E) a five-carbon sugar and phosphate group.
50) ______
51) According to the rules of complementary base pairing, a nucleotide
containing the base cytosine would pair with a nucleotide containing
the base
A) uracil.
B) adenine.
C) guanine.
D) thymine.
E) cytosine.
51) ______
52) The most important high-energy compound in cells is
A) adenosine triphosphate.
B) ribonucleic acid.
C) adenosine monophosphate.
D) deoxyribonucleic acid.
E) adenosine diphosphate.
52) ______
53) The bond between sodium and chloride in the compound sodium
chloride (NaCl) is
A) an ionic bond.
B) a nonpolar covalent bond.
C) a double ionic bond.
D) a double covalent bond.
E) a single covalent bond.
53) ______
54) When atoms complete their outer electron shell by sharing electrons,
they form
A) hydrogen bonds.
B) ionic bonds.
C) cations.
D) covalent bonds.
E) anions.
54) ______
55) Hydrophilic molecules readily associate with
A) water molecules.
B) lipid molecules.
C) hydrophilic molecules.
D) A and B
E) all of the above
55) ______
56) Carbohydrates, lipids, and proteins are classified as
A) acids.
B) bases.
C) organic molecules.
D) salts.
E) inorganic molecules.
56) ______
57) If an isotope of oxygen has 8 protons, 10 neutrons, and 8 electrons, its
mass number is
A) 16.
B) 26.
C) 8.
D) 12.
E) 18.
57) ______
58) Of the following choices, the pH of the least acidic solution is
A) 1.0.
B) 6.0.
C) 4.5.
D) 7.0.
58) ______
E) 2.3.
59) Of the following items, which has the greatest mass on Earth?
A) football
B) baseball
C) soccer ball
D) bowling ball
E) basketball
59) ______
60) Electrons have a ________ charge; protons have a ________ charge; and
neutrons have a ________ charge.
A) positive; negative; negative
B) negative; neutral; positive
C) negative; positive; neutral
D) negative; positive; positive
E) negative; neutral; neutral
60) ______
61) Identify cations from the following:
A) Na+
B) ClC) K+
D) A and B
E) A and C
61) ______
62) An anion would best be represented by which of the following?
A) K+
B) Na+
C) Cl-
62) ______
D) A and B
E) A and C
63) A needle floating on the surface of a glass of water best illustrates
A) anion action.
B) surface tension.
C) cation action.
D) chemical tension.
E) subatomic particles.
63) ______
64) An example of an organic substance is
A) sodium.
B) oxygen.
C) nitric oxide (NO).
D) table sugar.
E) table salt.
64) ______
65) An example of an inorganic substance is
65) ______
A)
B)
C)
D)
E)
fructose.
glycogen.
cholesterol.
lipid.
water.
66) In hydrolysis reactions, compounds react with
A) carbon causing decomposition.
B) water causing synthesis.
C) glucose causing decomposition.
D) water causing decomposition.
E) hydrogen causing decomposition.
66) ______
67) In dehydration reactions, compounds
A) convert water molecules to hydrogen and oxygen.
B) convert hydrogen and oxygen to water.
C) lose water molecules.
D) gain water molecules.
E) gain electrons.
67) ______
68) The body is approximately two-thirds water. Which property applied to
changing water temperatures keeps the body temperature stabilized?
A) lubrication
B) reactivity
C) thermal inertia
D) surface tension
E) kinetic energy
68) ______
69) If a molecule has two equal and opposite electrically charged poles
separated by a short distance, it is said to be
A) colloid.
B) hydrophilic.
C) hydrophobic.
D) tripolar.
E) dipolar.
69) ______
70) In an aqueous solution, cations move toward
A) sodium.
B) hydrogen ions.
C) water.
D) anions.
E) potassium.
70) ______
71) In an aqueous solution, sodium would move toward
A) sodium.
B) potassium.
C) water.
D) chloride.
E) A and B
71) ______
72) The chemical symbol indicating concentration is represented as
A) ().
B) [ ].
C) {}.
D) <>.
E) ||.
72) ______
73) Which has the greater concentration of hydrogen ions, a substance with
a pH of 5 or a substance with a pH of 4?
A) A pH of 4 is greater.
B) A pH of 5 is greater.
C) They are both equal; 4 and 5 are relative values.
D) A and B
E) none of the above
73) ______
74) Of the list below, which has the greatest concentration of hydroxide
ions?
A) one with a pH of 10
B) one with a pH of 7
C) one with a pH of 2
D) one with a pH of 13
E) one with a pH of 1
74) ______
75) Which pH is closest to neutral pH?
A) pH 6
B) pH 5
C) pH 4
75) ______
D) pH 3
E) pH 2
76) A functional group is best described as groupings of
A) elements that occur in a salt.
B) amino acids in a protein.
C) atoms that occur in low pH.
D) elements that occur in high pH.
E) atoms that occur repeatedly, such as carboxyl groups and amino
groups.
76) ______
77) A side chain is a group of
A) amino acids in a protein.
B) atoms attached to an atom in a principal chain or ring in an amino
acid.
C) elements in a protein.
D) proteins in an amino acid.
E) compounds in an amino acid.
77) ______
78) A side chain is often represented by the letter(s) ________ within a
structural formula.
A) R
B) DNA
C) RNA
D) C
E) S
78) ______
79) The term ________ means each enzyme catalyzes only one type of
reaction.
A) micelle
B) inertia
C) peptide
D) specificity
E) saturation
79) ______
80) The maximum rate of reaction is termed
A) synthesis.
B) saturation limit.
C) dehydration.
D) hydrolysis.
E) reversible.
80) ______
81) The average time between synthesis and recycling is known as
A) metabolism.
B) turnover rate.
C) specificity.
D) catabolism.
E) anabolism.
81) ______
82) Continuous removal and replacement of cells in a biological system is
termed
A) anabolic turnover.
B) metabolic turnover.
C) catabolic turnover.
D) metabolism.
E) A and C
82) ______
83) Identify the product formed from the phosphorylation of ADP.
A) deoxyribonucleic acid
B) adenosine triphosphate
C) adenosine diphosphate
D) adenine
E) ribose
83) ______
84) ADP + P →.
A) ATP
B) 2ADP
C) adenine
D) ADP
E) DNA
84) ______
85) The phosphorylation of AMP forms
A) 2ATP.
B) ribose.
C) ATP.
D) 2AMP.
E) ADP.
85) ______
86) Adenine and guanine are
A) purines represented by T and C.
B) pyrimidines represented by A and G.
C) pyrimidines represented by T and C.
D) carbohydrates represented by A and G.
E) purines represented by A and G.
86) ______
87) Dissolved gases are required in biological systems for
A) storage of energy.
87) ______
B)
C)
D)
E)
serving as structural components of bone.
serving as catalysts.
chemical messengers.
cellular metabolism.
88) Human red blood cells are removed and replaced every 120 days. This
is an example of
A) surface tension.
B) metabolic turnover.
C) thermal inertia.
D) functional groups.
E) specificity.
88) ______
89) What element is the most plentiful in the human body?
A) carbon
B) sulfur
C) oxygen
D) sodium
E) potassium
89) ______
90) What element is the second most abundant in the human body?
A) nitrogen
B) carbon
C) hydrogen
D) oxygen
E) calcium
90) ______
91) From the following group, indicate one containing all trace elements.
A) sulfur, chlorine, oxygen
B) silicon, fluorine, tin
C) boron, oxygen, carbon
D) cobalt, calcium, sodium
E) selenium, hydrogen, calcium
91) ______
92) The molecule NO is known as
A) noxious oxygen.
B) nitrate oxide.
C) nitric oxygen.
D) noxious oxide.
E) nitric oxide.
92) ______
93) The molecule CO2 is known as
93) ______
A)
B)
C)
D)
E)
carbon oxide.
carbon dioxide.
carbonated oxygen.
carbonized oxygen.
carbon monoxide.
94) The molecule H2 is known as
A) hydro.
B) helium.
C) hydrogen.
94) ______
D) hydroxide.
E) helios.
95) The molecule O2 is known as
A)
B)
C)
D)
E)
95) ______
oxide.
organic.
oxygen.
B and C
none of the above
96) The basic units of matter include ________ or ________.
A) neutrons; electrons
B) cells; tissues
C) protons; neutrons
D) atoms; elements
E) protons; electrons
96) ______
97) H2O is an example of a(n)
A) sodium molecule.
B) glucose molecule.
C) covalent formula.
D) ionic formula.
E) molecular formula.
97) ______
98) A(n) ________ accepts hydroxide ions in water and a(n) ________
releases hydrogen ions in water.
A) base; acid
B) acid; base
C) molecule; acid
D) compound; element
E) element; compound
98) ______
99) A nanometer is
A) 10-12 meter.
99) ______
B) 10-6 meter.
C) 10-8 meter.
D) 10-9 meter.
E) 10-10 meter.
100) An excess of hydrogen ions in the body fluids can have disastrous
results because
A) excess hydrogen ions can change the shape of large complex
molecules, rendering them nonfunctional.
B) excess hydrogen ions can disrupt tissue functions.
C) excess hydrogen ions can break chemical bonds.
D) all of the above
E) A and B only
100) _____
101) Artificial sweeteners
A) are inorganic sugar substitutes.
B) produce the same number of calories as the equivalent amount of
101) _____
sucrose.
C) are generally 100 or more times sweeter than sucrose.
D) are always some form of carbohydrate.
E) are naturally similar to sugars.
102) Alaska Natives have a lower incidence of heart disease even though
their diets are high in fat and cholesterol. This may be due to the large
amount of ________ in their diets.
A) steroids
B) omega-3 fatty acids
C) triglycerides
D) prostaglandins
E) oleic acid
102) _____
103) If an element is composed of atoms with an atomic number of 6 and a
mass number of 14, then a neutral atom of this element contains
A) 6 neutrons.
B) 14 protons.
C) 8 electrons.
D) 6 protons.
E) 14 electrons.
103) _____
104) One mole of any element
A) has the same mass.
B) has the same number of atoms.
C) has the same number of electrons.
D) has the same weight.
E) all of the above
104) _____
105) When electrons are transferred from one atom to another, and the two
atoms unite as a result of the electrostatic attraction,
A) an ion is formed.
B) an ionic bond is formed.
C) a hydrogen bond is formed.
D) a covalent bond is formed.
E) a molecule is formed.
105) _____
106) Calcium atoms have two electrons in the outermost shell. As a result,
you would expect calcium to form ions with a charge of
A) -2.
B) -1.
C) 0.
D) +2.
E) +1.
106) _____
107) Magnesium atoms have two electrons in the outermost shell and
chlorine atoms have seven. The compound magnesium chloride would
contain
A) 1 magnesium and 2 chlorine.
B) 2 magnesium and 7 chlorine.
C) 2 magnesium and 1 chlorine.
D) 1 magnesium and 1 chlorine.
E) impossible to tell without more information
107) _____
108) Each of the following statements concerning hydrogen bonds is true,
except one. Identify the exception.
108) _____
A) Hydrogen bonds can occur within a single molecule.
B) Hydrogen bonds can form between neighboring molecules.
C) Hydrogen bonds are important forces for holding large molecules
together.
D) Hydrogen bonds are responsible for many of the unique properties
of water.
E) Hydrogen bonds are strong attractive forces between hydrogen
atoms and negatively charged atoms.
109) In the reaction listed below, what coefficient needs to be added to
balance the equation? 6 CO2 + 6 H2O → C6H12O6 + ________ O2
A) 6
B) 10
C) 2
D) 4
109) _____
E) 8
110) Nonpolar organic molecules are good examples of
A) hydrophobic compounds.
B) molecules that will dissociate when placed into water.
C) electrolytes.
D) solutes.
E) hydrophilic compounds.
110) _____
111) An inorganic compound, when placed in water, dissociates 99 percent
forming hydrogen ions and anions. This substance would be
A) a strong base.
B) a strong acid.
C) a salt.
D) a weak base.
E) a weak acid.
111) _____
112) When a small amount of hydrochloric acid is added to a solution of
Na2HPO4, the pH of the solution does not change. The pH does not
112) _____
change when a small amount of NaOH is added either. Based on these
observations, all of the following are true concerning the compound
Na2HPO4, except
A) Na2HPO4 is able to accept extra hydrogen ions from the HCl.
B) Na2HPO4 acts as a buffer.
C) Na2HPO4 is able to donate hydrogen ions to the OH- from NaOH.
D) Na2HPO4 is a salt formed from reacting a strong base with a weak
acid.
E) Na2HPO4 adsorbs excess H+ and OH- directly onto the surface of
its crystalline structure.
113) Fructose
A) is a hexose.
B) is an isomer of glucose.
C) is found in male reproductive fluids.
D) all of the above
E) A and B only
113) _____
114) When two monosaccharides undergo a dehydration synthesis,
A) hydrolysis occurs.
B) a starch is formed.
114) _____
C) a disaccharide is formed.
D) a new monosaccharide is formed.
E) a polysaccharide is formed.
115) A shortage of cholesterol in the body would interfere with the formation
of
A) glycogen.
B) sex hormones.
C) proteins.
D) nucleic acids.
E) both A and C
115) _____
116) How would the lack of a cofactor for an enzyme affect that enzyme's
function?
A) The enzyme would function more quickly.
B) The enzyme's function would not be altered.
C) The enzyme would not be able to function.
D) The enzyme would cease to function after reaching a maximum
rate.
E) The enzyme would function more slowly.
116) _____
117) The nucleic acid RNA
A) contains the cell's genetic information.
B) is double stranded.
C) contains the pyrimidine uracil in place of thymine.
D) contains the pentose deoxyribose.
E) is restricted to the nucleus.
117) _____
118) You would expect to find proteoglycan molecules
A) acting as receptors on the surface of cell membranes.
B) in the secretions coating the respiratory tract.
C) functioning as hormones from the pancreas.
D) acting as antibodies to viruses.
E) functioning as enzymes in the stomach.
118) _____
SHORT ANSWER. Write the word or phrase that best completes each statement or answers
the question.
119) A(n) ________ is a substance that consists entirely of atoms with 119) ____________
the same atomic number.
120) The center of an atom is called the ________.
120) ____________
121) Electrons whirl around the center of the atom at high speed
forming a(n) ________.
121) ____________
122) Electrons in an atom occupy an orderly series of electron shells
or ________.
122) ____________
123) A(n) ________ is a combination of two or more atoms and has
different physical and chemical properties than its individual
atoms.
123) ____________
124) Ions with a positive charge are called ________.
124) ____________
125) Ions with a negative charge are called ________.
125) ____________
126) In a(n) ________ chemical bonds between atoms are broken as
atoms are rearranged in new combinations to form different
chemical substances.
126) ____________
127) Chemical reactions that release energy are called ________.
127) ____________
128) Chemical reactions that require energy are called ________.
128) ____________
129) ________ control the rate of chemical reactions that occur in the
human body.
129) ____________
130) In living cells, complex reactions proceed in a series of
interlocking steps called a(n) ________.
130) ____________
131) ________ molecules are compounds that contain carbon as the
primary structural atom.
131) ____________
132) ________ compounds do not contain carbon as the primary
structural atom.
132) ____________
133) A(n) ________ is a homogeneous mixture containing a solvent
and a solute.
133) ____________
134) ________ are soluble inorganic compounds whose ions will
conduct an electric current in solutions.
134) ____________
135) Molecules that readily dissolve in water are called ________.
135) ____________
136) Molecules that do not dissolve in water are called ________.
136) ____________
137) The ________ of a solution is the negative logarithm of the
hydrogen ion concentration expressed in moles per liter in the
solution.
137) ____________
138) ________ are compounds that in solution maintain pH within
given limits.
138) ____________
139) All fatty acids contain an arrangement of atoms called the
________ at one end of the chain.
139) ____________
140) In water, large numbers of fatty acids tend to form droplets
called ________.
140) ____________
141) ________ are lipid molecules that form biological membranes.
141) ____________
142) The molecule DNA contains a five-carbon sugar called
________.
142) ____________
143) The molecule RNA contains a five-carbon sugar called
________.
143) ____________
144) The purines found in DNA are ________ and ________.
144) ____________
145) The pyrimidine bases found in DNA are ________ and
________.
145) ____________
146) A(n) ________ is a covalent bond that stores an unusually large
amount of energy.
146) ____________
147) In the process of ________ a phosphate group is attached to a
molecule.
147) ____________
148) The hydrolysis of ATP yields the molecule ________.
148) ____________
149) The ________ of a radioactive substance is the time required for
a 50 percent reduction in the rate of radiation emission.
149) ____________
150) Identify the three components of a nucleotide.
150) ____________
151) Explain the role of water molecules in polysaccharide
formation.
151) ____________
152) What role do buffer systems play in the human body?
152) ____________
ESSAY. Write your answer in the space provided or on a separate sheet of paper.
153) Why is it life-threatening to have a high fever?
154) How does the DNA molecule control the appearance and function of a cell?
155) The element sulfur has an atomic number of 16 and an atomic weight of 32. How
many neutrons are in the nucleus of a sulfur atom? If sulfur forms covalent bonds
with hydrogen, how many hydrogen atoms can bond to one sulfur atom?
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
B
D
E
D
B
A
C
E
B
C
A
B
E
C
D
B
C
B
B
C
A
C
C
C
C
C
D
C
A
C
D
E
B
B
B
B
D
E
D
B
B
B
B
E
B
A
A
D
E
B
C
52)
53)
54)
55)
56)
57)
58)
59)
60)
61)
62)
63)
64)
65)
66)
67)
68)
69)
70)
71)
72)
73)
74)
75)
76)
77)
78)
79)
80)
81)
82)
83)
84)
85)
86)
87)
88)
89)
90)
91)
92)
93)
94)
95)
96)
97)
98)
99)
100)
101)
102)
103)
A
A
D
A
C
E
B
D
C
E
C
B
D
E
D
C
C
E
D
D
B
A
D
A
E
B
A
D
B
B
B
B
A
E
E
E
B
C
B
B
E
B
C
C
D
E
A
D
D
C
B
D
104)
105)
106)
107)
108)
109)
110)
111)
112)
113)
114)
115)
116)
117)
118)
119)
120)
121)
122)
123)
124)
125)
126)
127)
128)
129)
130)
131)
132)
133)
134)
135)
136)
137)
138)
139)
140)
141)
142)
143)
144)
145)
146)
147)
148)
149)
150)
151)
152)
B
B
D
A
E
A
A
B
E
E
C
B
C
C
B
element
nucleus
electron cloud
energy levels
compound
cations
anions
chemical reaction
exergonic
endergonic
Enzymes
pathway
Organic
Inorganic
solution
Electrolytes
hydrophilic
hydrophobic
pH
Buffers
carboxylic acid group
micelles
Structural lipids (or phospholipids)
deoxyribose
ribose
adenine; guanine
thymine; cytosine
high-energy bond
phosphorylation
ADP
half-life
pentose; phosphate group; nitrogenous base
Water molecules are released in the dehydration synthesis of polysaccharides.
Buffer systems maintain pH within normal limits by removing or replacing hydrogen ions
as needed.
153) A high body temperature can be life-threatening because the heat can cause certain
proteins, such as vital enzymes, to become denatured. When this occurs, the proteins
beco me nonfunctional and if they catalyze reactions that are necessary for life, life will cease.
154) The DNA molecule controls the manufacture of enzymes and structural proteins. By
controlling the manufacture of structural proteins, the DNA is able to influence the
physical appearance of a cell. By controlling the production of enzymes, the DNA is able to
control all aspects of cellular metabolism and thus control the activity and biological
functions of the cell.
155) The number of neutrons in an atom is equal to the atomic weight minus the atomic
number. Thus, sulfur has 32 - 16 = 16 neutrons. The atomic number indicates the number of
protons, so a neutral sulfur atom contains 16 protons plus 16 electrons to balance the
protons electrically. The electrons would be distributed as follows: 2 in the first level, 8 in
the second level, and the remaining 6 in the third level. To achieve a full 8 electrons in the
third (outermost) level, the sulfur atom can accept 2 electrons in an ionic bond or can share
2 electrons in a covalent bond. Because hydrogen atoms can share one electron in a
covalent bond, the sulfur atom can form two covalent bonds with hydrogen, one with each
of two hydrogen atoms.