Name: 
 

Biochemistry PCC


Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 
At what temperature is water most dense?
a.
0 degrees Celsius
b.
1 degrees Celsius
c.
4 degrees Celsius
d.
10 degrees Celsius
e.
100 degrees Celsius
 

 2. 
Which property of water enables living things to survive in it?
a.
high heat of vaporization
b.
high specific heat
c.
degree of surface tension
d.
cohesion
e.
density of ice
 

 3. 
Which characteristic of water makes the existence of pH possible?
a.
ionization
b.
polarity
c.
adhesion
d.
cohesion
e.
None of the above.
 

 4. 
Which of the following types of biologist would need an understanding of chemistry?
a.
molecular biologist
b.
ecologist
c.
evolutionary biologist
d.
botanist
e.
All of the above.
 

 5. 
All of the following are inorganic compounds except:
a.
glucose.
b.
hydrochloric acid.
c.
sodium chloride.
d.
sodium hydroxide.
e.
water.
 

 6. 
An element is defined as a substance that:
a.
is composed of more than one kind of atom.
b.
is held together by covalent bonds.
c.
cannot be broken into simpler substances by chemical reactions.
d.
cannot burn.
e.
is soluble in both acid and water.
 

 7. 
Which of the following determines the type of element?
a.
the number of electrons
b.
the number of protons
c.
the number of neutrons
d.
the number of valence electrons
e.
the number of energy levels
 

 8. 
Which of the following elements is not responsible for a significant portion of the mass of living organisms?
a.
O
b.
S
c.
N
d.
H
e.
C
 

 9. 
An element found in minute quantities in living organisms is called:
a.
a heavy element.
b.
a vitamin.
c.
an organic compound.
d.
an isotope.
e.
a trace element.
 

 10. 
Select the incorrectly matched pair:
a.
The 1st principal energy level contains 1 orbital.
b.
The 2nd principal energy level contains 4 orbitals.
c.
The 1st principal energy level contains a maximum of 2 electrons.
d.
The 2nd energy level contains a maximum of 10 electrons.
e.
All of the above are correctly matched.
 

 11. 
Chlorine has seven electrons in its valence shell. The number of electrons it must gain to complete its valence shell is:
a.
one.
b.
two.
c.
three.
d.
seven.
e.
eight.
 

 12. 
An atom has six protons and eight neutrons. Its atomic mass is ____________ atomic mass units.
a.
two
b.
four
c.
six
d.
eight
e.
fourteen
 

 13. 
This determines the chemical properties of an element:
a.
the atomic number.
b.
the atomic weight.
c.
the number of energy levels.
d.
the number of valence electrons.
e.
orbitals.
 

 14. 
The difference between an electrically neutral atom and an ion is that:
a.
an ion has an unequal number of protons and electrons, while an atom has an equal number.
b.
an ion has an equal number of protons and electrons, while an atom has an unequal number.
c.
an atom has an unequal number of neutrons and protons, while an ion has an equal number.
d.
an atom has its electrons in orbitals, while an ion has its electrons in its nucleus.
e.
an atom must have an equal number of neutrons and electrons, while an ion does not.
 

 15. 
The difference between a stable isotope and a radioisotope is that:
a.
the stable isotope emits radiation.
b.
the radioisotope emits radiation.
c.
the stable isotope emits light.
d.
the stable isotope absorbs radiation.
e.
the radioisotope has an unequal number of protons and electrons.
 
 
Figure 02-01
Use the figure below to answer the corresponding questions.

nar001-1.jpg
 

 16. 
Figure 02-01 represents:
a.
two isotopes of the same element.
b.
two different elements.
c.
two different ions.
d.
an acid and a base.
e.
a cation and an anion.
 

 17. 
The atomic mass of the atom identified as A in Figure 02-01 is:
a.
2.
b.
6.
c.
8.
d.
12.
e.
18.
 

 18. 
The difference between the two atoms in Figure 02-01 is:
a.
pH.
b.
the number of electrons.
c.
the number of protons.
d.
the number of neutrons.
e.
electric charge.
 

 19. 
Radioisotopes are used in all of the following scientific applications except:
a.
dating fossils.
b.
determining the sequence of genetic information in DNA.
c.
localization of a drug, such as marijuana.
d.
the treatment of cancer.
e.
monitoring changes in the salinity of an estuary.
 

 20. 
Isotopes differ from each other with respect to the number of:
a.
protons.
b.
electrons.
c.
neutrons.
d.
protons and electrons.
e.
neutrons and protons.
 

 21. 
When a chemical reaction is at equilibrium:
a.
the forward reaction is going faster.
b.
the reverse reaction is going faster.
c.
the forward and reverse reactions are proceeding at equal rates.
d.
the forward reaction stops.
e.
the reverse reaction stops.
 

 22. 
Any chemical interaction between atoms:
a.
involves neutrons.
b.
may potentially involve any electron.
c.
involves protons.
d.
involves only valence electrons.
e.
involves only the nuclear subatomic particles.
 

 23. 
The molecular mass of C6H12O6 is 180 amu. 0.25 moles of this substance contain:
a.
180 daltons.
b.
45 g.
c.
1.8 g.
d.
45 daltons.
e.
180 g.
 

 24. 
How many molecules are present in one mole of C6H12O6?
a.
1.7 ´ 10-10 molecules
b.
1.3 ´ 1010 molecules
c.
5 molecules
d.
1.7 ´ 1022 molecules
e.
6.02 ´ 1023 molecules
 
 
Figure 02-02
Use the figure below to answer the corresponding questions.

nar002-1.jpg
 

 25. 
Figure 02-02 represents:
a.
elemental helium.
b.
molecular hydrogen.
c.
molecular helium.
d.
a water molecule.
e.
molecular oxygen.
 

 26. 
The type of bond illustrated in Figure 02-02 is:
a.
an ionic bond.
b.
a polar bond.
c.
a single covalent bond.
d.
a hydrogen bond.
e.
a double covalent bond.
 

 27. 
Select the covalent bond that involves 2 electrons:
a.
single
b.
double
c.
triple
d.
Both A and B.
e.
Both A and C.
 

 28. 
The representation H - O - H is known as:
a.
a structural formula.
b.
a simplest formula.
c.
a molecular formula.
d.
a Lewis structure.
e.
an orbital diagram.
 

 29. 
Which of the following choices correctly identifies a reactant in the following chemical equation? CO2 + H2O « H2CO3
a.
carbonic acid
b.
oxygen
c.
water
d.
sugar
e.
carbon monoxide
 

 30. 
In a chemical reaction, the product is:
a.
generally written on the right side of the equation.
b.
always in equilibrium with the reactants.
c.
the substance that is generated by the reaction.
d.
only joined by an ionic bond.
e.
Both A and C.
 

 31. 
A covalent bond:
a.
can form only between identical atoms.
b.
involves a sharing of only one pair of electrons.
c.
is always polar.
d.
may be polar or nonpolar depending on the atoms involved.
e.
always forms between identical molecules.
 

 32. 
In a water molecule, because oxygen is more electronegative than hydrogen, the shared electrons are more commonly found around the ____________ nucleus than the ____________ nucleus.
a.
oxygen; hydrogen
b.
hydrogen; oxygen
c.
hydrogen; other hydrogen
d.
oxygen; nitrogen
e.
nitrogen; oxygen
 

 33. 
The covalent bond between a hydrogen atom and the oxygen atom in water is formed when:
a.
hydrogen gains an electron from oxygen.
b.
hydrogen and oxygen share an electron pair.
c.
hydrogen and oxygen both lose electrons from their outer shells.
d.
hydrogen and oxygen both gain electrons in their outer shells.
e.
hydrogen gains an electron from oxygen.
 

 34. 
Covalently bonded atoms with similar electronic negativities are:
a.
ionic.
b.
polar.
c.
nonpolar.
d.
partially positive.
e.
partially negative.
 

 35. 
An atom becomes a cation if:
a.
it gains one or more electron.
b.
it loses one or more electron.
c.
it shares electrons.
d.
one or more of its electrons changes energy levels.
e.
it emits radiation.
 

 36. 
In the formation of common table salt, sodium and chlorine interact because:
a.
sodium and chlorine share a pair of electrons.
b.
sodium and chlorine share two pairs of electrons.
c.
chlorine donates seven electrons to sodium.
d.
there is no electron exchange.
e.
sodium donates one electron to chlorine.
 

 37. 
Table salt dissolves easily in water because:
a.
water can form covalent linkages with salt molecules.
b.
water can remove electrons from the chloride ion, which causes the latter to dissociate from the sodium and dissolve.
c.
water can add electrons to the sodium ion.
d.
water is polar and salt is nonpolar. Nonpolar compounds are more soluble in polar solvents because they are able to form strong covalent bonds that result in a breaking up of the molecule being dissolved.
e.
the partial positive charge of the hydrogens in the water molecule can associate with the negative charge of the chloride ion, and the partial negative charge of the oxygen of the water molecule can associate with the positive charge of the sodium atom.
 

 38. 
Which one of the following atoms would most likely be involved in an ionic bond?
a.
hydrogen
b.
oxygen
c.
sodium
d.
Both A and B.
e.
Both A and C.
 

 39. 
The process whereby water molecules surround ions during the process of dissolving is called:
a.
reduction.
b.
hydration.
c.
buffering.
d.
oxidation.
e.
vaporization.
 

 40. 
Which component becomes oxidized in the following chemical reaction?
4 Fe + 3 O2 ® 2 Fe2O3
a.
water
b.
iron
c.
oxygen
d.
rust
e.
hydrogen
 

 41. 
Which component is the oxidizing agent in the following chemical reaction?
4 Fe + 3 O2 ® 2 Fe2O3
a.
water
b.
iron
c.
oxygen
d.
rust
e.
hydrogen
 

 42. 
Which of the following statements is not correct?
a.
Water heats up and cools down very quickly.
b.
The amount of heat required to raise the temperature of 1 g of water 1 °C is one calorie.
c.
Due to hydrogen bonds, water has a high surface tension.
d.
Large bodies of water have relatively constant temperatures.
e.
When one gram of water evaporates, it removes heat.
 

 43. 
It takes one calorie of heat to raise the temperature of one gram of water one degree Celsius at sea level. This is referred to as the _______________________ of water.
a.
heat of fusion
b.
heat of vaporization
c.
specific heat
d.
heat of transformation
e.
heat of homeostasis
 

 44. 
Which characteristic of water molecules directly contributes to the remarkable "water walking" success of the aquatic insects pictured in the accompanying figure?

mc044-1.jpg
a.
hydrogen bonds
b.
capillary action
c.
nonpolar covalent bonds
d.
ionic bonds
e.
adhesive forces
 

 45. 
The cohesiveness between water molecules is due largely to:
a.
hydrogen bonds.
b.
polar covalent bonds.
c.
nonpolar covalent bonds.
d.
ionic bonds.
e.
hydrophobic interactions.
 

 46. 
A stalk of celery is placed in a solution of blue colored dye. After one hour, the leaves have blue fluid in their veins. Which property of water is being demonstrated?
a.
adhesion and cohesion
b.
evaporation and cooling
c.
lower density as a solid than as a liquid
d.
high specific heat
e.
surface tension
 

 47. 
Evaporative cooling is a process whereby ____________ moving ____________ molecules vaporize, thus ____________ large amounts of heat.
a.
slow; water; adding
b.
fast; water; removing
c.
slow; oxygen; adding
d.
fast; oxygen; removing
e.
fast; carbon dioxide; removing
 

 48. 
In a mixture, which one would be present in the least amount?
a.
solvent
b.
solute
c.
water
d.
Both A and B.
e.
Both A and C.
 

 49. 
This characteristic of a molecule determines the ability of hydrogen bonds to form between it and hydrogen:
a.
A non polar atom
b.
An atom with a partial positive charge
c.
An atom with a partial negative charge
d.
None of the above.
e.
All of the above.
 

 50. 
A pH of 4 is ____________ times more ____________ than a pH of 7.
a.
3; basic
b.
3; acidic
c.
1000; neutral
d.
1000; basic
e.
1000; acidic
 

 51. 
What is the OH- concentration of a solution having a pH of 2?
a.
1 ´ 10-12
b.
1 ´ 10-10
c.
1 ´ 10-7
d.
1 ´ 10-2
e.
1 ´ 10-1
 

 52. 
When a small amount of hydrochloric acid (HCl) is added to a solution of Na2HPO4, the pH of the solution does not change markedly. The pH also does not change drastically when a small amount of sodium hydroxide (NaOH) is added to this same solution. Based on these observations, the compound Na2HPO4 is:
a.
able to donate hydrogen atoms to HCl.
b.
able to remove hydrogen ions from the OH- of NaOH.
c.
acting as a buffer.
d.
an enzyme facilitating the reaction between HCl and NaOH.
e.
All of the above.
 

 53. 
A salt is a compound in which the hydrogen ion of _________________ is replaced by some other cation.
a.
a base
b.
an acid
c.
an anion
d.
a hydroxide ion
e.
water
 

 54. 
Which concentration(s) results in a pH of 7?
a.
higher concentrations of hydrogen ions than hydroxide ions
b.
higher concentrations of hydroxide ions than hydrogen ions
c.
equal concentrations of hydroxide ions than hydrogen ions
d.
Both A and B.
e.
None of the above.
 

 55. 
Identify the chemical(s) that act(s) as a buffer in human blood:
a.
bicarbonate
b.
hydrogen ions
c.
carbon dioxide
d.
water
e.
None of the above.
 

 56. 
Identify the hydrogen ion concentration that represents the lowest pH from the following list:
a.
1 ´ 10-3
b.
1 ´ 10-4
c.
1 ´ 10-7
d.
1 ´ 10-11
e.
1 ´ 10-14
 

 57. 
Which of the following has a pH closest to that of human blood?
a.
beer
b.
coffee
c.
rain water
d.
sea water
e.
oven cleaner
 

 58. 
Which of the following would most likely form electrolytes in water?
a.
glucose
b.
ethanol
c.
An organic compound
d.
An inorganic compound
e.
None of the above.
 

 59. 
Which of the following is not a property of carbon?
a.
Carbon-to-carbon bonds are limited to single bonds.
b.
Carbon has four valence electrons.
c.
Carbon can form bonds to various other atoms.
d.
Two carbon atoms can share three electron pairs with each other.
e.
Carbon-to-carbon bonds are strong.
 

 60. 
What aspect of long carbon chains makes them ideal for forming the backbones of long biomolecules?
a.
The carbon atom itself is strong and hard to split.
b.
Carbon can form a maximum of five covalent bonds with other atoms.
c.
Carbons can form a maximum of three covalent bonds with other atoms.
d.
Carbon-to-carbon covalent bonds are strong.
e.
Carbon-to-carbon hydrogen bonds are weak and transitory.
 

 61. 
The highly polarized nature of compounds containing carboxyl groups can be attributed to:
a.
the presence of two highly electronegative carbon atoms.
b.
the presence of two highly electropositive carbon atoms.
c.
the presence of two highly electronegative oxygen atoms.
d.
the presence of two highly electropositive oxygen atoms.
e.
None of the above.
 

 62. 
The number of electron pairs shared between carbon 2 and 3 in the accompanying figure is:

mc062-1.jpg
a.
one.
b.
one and a half.
c.
two.
d.
three.
e.
None of the above.
 

 63. 
The two molecules in the following figure represent:

mc063-1.jpg
a.
ionized structures.
b.
enantiomers.
c.
secondary structures.
d.
geometric isomers.
e.
polymers.
 

 64. 
This functional group is weakly basic because it can accept an H+ ion:
a.
hydroxyl
b.
carbonyl
c.
amino
d.
phosphate
e.
sulfhydryl
 

 65. 
This functional group forms cross bridges that help stabilize protein tertiary structure:
a.
hydroxyl
b.
carbonyl
c.
amino
d.
phosphate
e.
sulfhydryl
 

 66. 
The chemical interactions of large hydrocarbons are largely determined by:
a.
their solubility in water.
b.
their functional groups.
c.
their polar nature.
d.
isomerization of these hydrocarbons into other forms.
e.
the hydrogens bonded to the carbon atoms.
 

 67. 
Hydrocarbons are hydrophobic because:
a.
the covalent bonds between hydrogen and carbon are nonpolar.
b.
they contain functional groups.
c.
they exist as isomers.
d.
Both A and B.
e.
Both A and C.
 

 68. 
Which pair is mismatched?
a.
monsaccharide:maltose
b.
disaccharide:sucrose
c.
polysaccharide:cellulose
d.
None of these pairs are correctly matched.
e.
All of these pairs are correctly matched.
 

 69. 
Which of these terms is most inclusive?
a.
monosaccharide
b.
starch
c.
polysaccharide
d.
disaccharide
e.
carbohydrate
 

 70. 
Glucose dissolves in water because:
a.
it ionizes.
b.
it is a polysaccharide.
c.
it has polar hydroxyl groups that interact with polar water molecules.
d.
it has a very reactive primary structure.
e.
it is hydrophobic.
 

 71. 
Carbohydrate molecules:
a.
serve as structural components of human cell walls.
b.
form the regulatory compounds known as enzymes.
c.
are a source of energy.
d.
help protect vital organs from damage.
e.
contain the genetic information of a cell.
 

 72. 
A chemical reaction in which organic compounds are synthesized from their building blocks is called:
a.
hydrolysis.
b.
condensation.
c.
oxidation.
d.
reduction.
e.
dissociation.
 
 
Figure 03-01
Use the figure below to answer the corresponding questions.

nar003-1.jpg
 

 73. 
The process illustrated in Figure 03-01 is called:
a.
condensation.
b.
protein synthesis.
c.
hydrolysis.
d.
dehydration synthesis.
e.
denaturation.
 

 74. 
The products of the process in Figure 03-01 are:
a.
amino acids.
b.
molecules of glycerol.
c.
representative of a glycoside linkage.
d.
enzymes.
e.
monosaccharides.
 

 75. 
Which one of the following carbohydrates is the most structurally complex?
a.
sucrose
b.
fructose
c.
cellulose
d.
glucose
e.
a disaccharide
 

 76. 
In which of the following reactions must the equivalent of a water molecule be added in order to break a bond?
a.
fatty acids + glycerol ® fat
b.
glucose + fructose ® sucrose
c.
glycogen ® glucose
d.
alanine + glycine ® dipeptide
e.
glucose ® cellulose
 

 77. 
Which of the following illustrates hydrolysis?
a.
the reaction of two monosaccharides to form a disaccharide
b.
the reaction of two amino acids to form a dipeptide
c.
the reaction of a hydrogen atom and a hydroxide ion to form water
d.
the reaction of a fat to form glycerol and fatty acids
e.
the formation of ATP from ADP and inorganic phosphate
 

 78. 
The difference between a hexose and a pentose is that:
a.
a hexose is saturated, and a pentose is undersaturated.
b.
a hexose is hydrophilic, and a pentose is hydrophobic.
c.
a hexose always has six hydroxyl groups, and a pentose always has five.
d.
a hexose always has six carbons, but a pentose always has five carbons.
e.
a hexose can be polymerized, but a pentose cannot.
 

 79. 
Monosaccharides are water soluble because:
a.
they contain a large number of methyl groups.
b.
they have a large number of polar hydroxyl groups.
c.
they have at least one double bond between adjacent carbons.
d.
they have large numbers of nonpolar carbons in their backbones.
e.
they can form ring structures.
 

 80. 
A carbohydrate energy storage molecule found in animal liver and muscle cells is:
a.
starch.
b.
glycogen.
c.
cellulose.
d.
fatty acids.
e.
cholesterol.
 

 81. 
Amyloplasts are organelles that store:
a.
fat.
b.
starch.
c.
protein.
d.
lipids.
e.
DNA.
 

 82. 
The major function(s) of lipids includes:
a.
storing energy.
b.
serving as structural components of cellular membranes.
c.
serving as hormones.
d.
Both A and B.
e.
A, B, and C are correct.
 

 83. 
The hydrolysis of triacylglycerol will yield:
a.
three fatty acids and one glycerol.
b.
three glycerols and one fatty acid.
c.
two fatty acids and three glycerols.
d.
one fatty acid, one amino acid, and one glucose.
e.
one fatty acid, one phosphate, and one glycerol.
 

 84. 
A molecule of a saturated triacylglycerol contains:
a.
the maximum number of double bonds between carbons in the fatty acid chains.
b.
the maximum number of triple bonds between carbons in the fatty acid chains.
c.
the maximum number of hydrogen atoms in the fatty acid chains.
d.
fatty acid chains with both amino and carboxyl groups.
e.
alternating single and double bonds between carbons in the fatty acid chains.
 

 85. 
Which of the following statements concerning unsaturated fats is correct?
a.
They are more common in animals.
b.
They have no double bonds in the carbon chains of their fatty acids.
c.
They are generally liquids at room temperature.
d.
They contain more hydrogen than do saturated fats having the same number of carbon atoms.
e.
They have fewer fatty acids per fat molecule than do saturated fats.
 

 86. 
The major difference between a structural lipid, such as those in cell membranes, and a storage fat is the fact that the structural lipid:
a.
most commonly contains phosphate.
b.
does not contain glycerol.
c.
has four fatty acids attached to glucose.
d.
is entirely hydrophobic.
e.
is nonpolar.
 

 87. 
An amphipathic molecule has:
a.
two polar ends.
b.
two hydrophobic ends.
c.
a hydrophobic and a hydrophilic portion.
d.
only one hydrophobic end.
e.
only one hydrophilic end.
 

 88. 
The most abundant molecules in this structure are:

mc088-1.jpg
a.
structural proteins.
b.
polysaccharides.
c.
triacylglycerols.
d.
phospholipids.
e.
polypeptides.
 

 89. 
Which of the following molecules is not grouped with the lipids?
a.
prostaglandins
b.
steroids
c.
cholesterol
d.
carotenoids
e.
None of the above, all are lipids.
 

 90. 
The hydrogenation process used to make margarine from cooking oil produces fatty acids that:
a.
are known to increase the risk of cardiovascular disease.
b.
contain fewer double bonds.
c.
can contain rearrange double bonds to the cis configuration.
d.
Both A and B are correct.
e.
A, B, and C are correct.
 

 91. 
Which statement is false?
a.
Trans fatty acids are unsaturated.
b.
Trans fatty acids are more solid at room temperature than cis fatty acids.
c.
Unsaturated fatty acids are liquid at room temperature.
d.
Saturated fatty acids are solid at room temperature.
e.
All of these statements are true.
 

 92. 
The major function(s) of proteins includes:
a.
catalyzing chemical reactions.
b.
controlling the expression of genes.
c.
strengthening and protecting cells and tissues.
d.
Both A and B.
e.
A, B, and C are correct.
 

 93. 
There are 20 different amino acids in the proteins that make up the tissues of living organisms. The primary difference between these amino acids is in their:
a.
R or variable groups.
b.
number of potassium groups.
c.
number of phosphate groups.
d.
number of carbonyl groups.
e.
number of asymmetric carbons.
 
 
Figure 03-02
Use the figure below to answer the corresponding questions.

nar004-1.jpg
 

 94. 
In Figure 03-02, ionic attractions would form between the R groups of which amino acids?
a.
1 and 3
b.
2 and 4
c.
3 and 5
d.
4 and 6
e.
None of the above.
 

 95. 
Hydrophobic interactions would occur between the R groups of which two amino acids in Figure 03-02?
a.
1 and 4
b.
2 and 5
c.
3 and 6
d.
2 and 4
e.
3 and 5
 

 96. 
Which of the following is responsible for the alpha-helical structure of proteins?
a.
hydrophobic interactions
b.
nonpolar covalent bonds
c.
ionic interactions
d.
hydrogen bonds
e.
polar covalent bonds
 

 97. 
At which level of protein structure are peptide bonds most important?
a.
primary
b.
secondary
c.
tertiary
d.
quaternary
e.
globular
 

 98. 
Proteins with alpha helical forms exhibit this property:
a.
strength
b.
elasticity
c.
heat stability
d.
rigidity
e.
All of the above.
 

 99. 
Which of the following would help stabilize a protein the most?
a.
alpha helix
b.
beta pleated sheet
c.
hydrogen bonds
d.
hydrophobic interactions
e.
disulfide bonds
 

 100. 
Some proteins are important biological buffers because:
a.
they react with water to produce carbon dioxide, which neutralizes acids.
b.
they contain weakly acidic and weakly basic groups.
c.
they are able to absorb great amounts of carbon dioxide during condensation reactions.
d.
they produce carbonic acid upon hydrolysis.
e.
All of the above.
 

 101. 
The tertiary structure of proteins is typified by the:
a.
association of several polypeptide chains by weak bonds.
b.
order in which amino acids are joined in a peptide chain.
c.
bonding of two amino acids to form a dipeptide.
d.
folding of a peptide chain to form an alpha helix.
e.
three-dimensional shape of an individual polypeptide chain.
 

 102. 
All of the following types of chemical bonds are responsible for maintaining the tertiary structure of this polypeptide except:

mc102-1.jpg
a.
ionic bonds.
b.
hydrogen bonds.
c.
hydrophobic interactions.
d.
disulfide bonds.
e.
peptide bonds.
 

 103. 
Regulatory proteins:
a.
defend against foreign invaders.
b.
store nutrients.
c.
catalyze a specific chemical reaction.
d.
control the expression of specific genes.
e.
strengthen and protect cells and tissues.
 

 104. 
Molecular chaperones are proteins that mediate the folding process of:
a.
other proteins.
b.
amino acids.
c.
lipids.
d.
DNA.
e.
sugars.
 

 105. 
The following amino acid would be characterized as __________ based on the chemical properties of its side chain.

mc105-1.jpg
a.
nonpolar
b.
acidic
c.
basic
d.
hydrophilic
e.
electrically charged
 

 106. 
Which of the following statements is true of proteins?
a.
Proteins lose some or all of their normal activity if their three-dimensional structure is disrupted.
b.
Proteins are composed of ribose, phosphate, and a nitrogen-containing base.
c.
The activity of proteins is independent of temperature and pH.
d.
Denaturation is usually reversible.
e.
All proteins are enzymes.
 

 107. 
If the differently shaded portions of this molecule represent different polypeptide chains, then this figure is representative of:

mc107-1.jpg
a.
an amino acid.
b.
the quaternary structure of a protein.
c.
a steroid hormone.
d.
cellulose.
e.
a carotenoid.
 

 108. 
Which of the following statements is false?
a.
DNA is usually composed of two nucleotide strands.
b.
DNA contains deoxyribose.
c.
DNA does not normally contain uracil.
d.
The nucleotides of DNA are linked by phosphodiester linkages.
e.
DNA does not normally contain a phosphate group.
 

 109. 
ATP is important in living organisms because:
a.
like all other nucleic acids, it stores hereditary information.
b.
like RNA, it acts as a source code for the formation of proteins.
c.
it can transfer some of its energy to other chemicals.
d.
it is an important structural component of cell membranes.
e.
it is easily converted to starch for long-term storage.
 

 110. 
Which of the following statements best summarizes the differences between RNA and DNA?
a.
RNA is a protein and DNA is a nucleic acid.
b.
DNA is a polymer and RNA is a monomer.
c.
DNA comprises the genes, while RNA is a direct participant in the process of protein synthesis.
d.
RNA is a single-stranded form of DNA.
e.
DNA is the primary energy currency of all cells.
 

 111. 
Analysis of a certain complex compound shows that it contains phosphate groups, ribose groups, and pyrimidines. Based on this information, which of the following is the best description of this compound?
a.
It is most likely ribonucleic acid.
b.
It is DNA.
c.
It is an inorganic compound.
d.
It contains thymine.
e.
It is a polypeptide.
 

 112. 
Which of the following are most directly arranged from DNA structure?
a.
polysaccharides
b.
polypeptides
c.
nucleotides
d.
triglycerides
e.
fatty acids
 

 113. 
This molecule transmits heredity information:
a.
cholesterol
b.
adenosine triphosphate
c.
nucleic acid
d.
fatty acid
e.
polysaccharide
 
 
Figure 03-03
Use the figure to answer the corresponding questions.
nar005-1.jpg
 

 114. 
The molecular fragment represented in Figure 03-03 is:
a.
ATP.
b.
RNA.
c.
a protein.
d.
a nucleotide.
e.
a polysaccharide.
 

 115. 
The type of connection between the atoms at the point labeled 1 in Figure 03-03 is:
a.
a peptide bond.
b.
a glycoside linkage.
c.
a disulfide bond.
d.
a phosphodiester linkage.
e.
a hydrogen bond.
 

 116. 
Which portion of the following molecule is easily transferred and therefore responsible for the energy transfer property of this molecule?

mc116-1.jpg
a.
1
b.
2
c.
3
d.
1 and 2
e.
None of the above.
 

 117. 
Ester linkages would not be formed during condensation reactions that produce:
a.
polysaccahrides.
b.
triacylglycerols.
c.
polypeptides.
d.
nucleic acids.
e.
All of the above contain ester linkages that are formed during condensation reactions.
 

 118. 
Which monomer is incorrectly matched with the corresponding polymer?
a.
Amino acids are used to build proteins.
b.
Monosaccharides are used to build polysaccharides.
c.
Fatty acids are used to build nucleic acids.
d.
Glucose molecules are used to build starches.
e.
All of these monomers are correctly matched with the corresponding polymer.
 



 
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