Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1)
Select the most correct statement regarding nucleic acids.
1)
A)
Three forms exist: DNA, RNA, and tDNA.
B)
RNA is a long, single-stranded molecule made up of the bases A, T, G, and C.
C)
tDNA is considered a molecular slave of DNA during protein synthesis.
D)
DNA is a long, double-stranded molecule made up of A, T, G, and C bases.
2)
An atom with a valence of 3 may have a total of ____ ____ electrons.
2)
A)
13
B)
3
C)
17
D)
8
3)
Which of the following is not considered a factor in influencing a reaction rate?
3)
A)
temperature
B)
time
C)
concentration
D)
particle size
4)
Which of the following does not describe uses for the ATP molecule?
4)
A)
pigment structure
B)
transport across membranes
C)
mechanical work
D)
chemical work
5)
________ is fat soluble, produced in the skin on exposure to UV radiation, and necessary for normal
bone growth and function.
5)
A)
Vitamin A
B)
Vitamin D
C)
Vitamin K
D)
Cortisol
6)
Stress proteins are a type of protein called ___ _____.
6)
A)
coenzymes
B)
eicosanoids
C)
cofactors
D)
chaperones
7)
Which of the following is a neutralization reaction?
7)
A)
NaOH
Na++ OH-
B)
HCl + NaOH
NaCl + H2O
C)
HCl
H++ Cl-
D)
NH3+ H+
NH4+2
8)
What is the ratio of fatty acids to glycerol in neutral fats?
8)
A)
3:1
B)
4:1
C)
2:1
D)
1:1
9)
What is a chain of more than 50 amino acids called?
9)
A)
polypeptide
B)
protein
C)
nucleic acid
D)
polysaccharide
10)
Carbohydrates and proteins are built up from their basic building blocks by the ________.
10)
A)
addition of a carbon atom between each two units
B)
removal of a carbon atom between each two units
C)
removal of a water molecule between each two units
D)
addition of a water molecule between each two units
11)
Which protein types are vitally important to cell function in all types of stressful circumstances?
11)
A)
structural proteins
B)
regulatory prote ins
C)
catalytic proteins
D)
molecular chaperones
12)
Choose the answer that best describes fibrous proteins.
12)
A)
are cellular catalysts
B)
are very stable and insoluble in water
C)
are usually called enzymes
D)
rarely exhibit secondary structure
13)
Carbohydrates are stored in the liver and muscles in the form of ________.
13)
A)
cholesterol
B)
glucose
C)
glycogen
D)
triglycerides
14)
Which of the following would be regarded as an organic molecule?
14)
A)
CH4
B)
NaOH
C)
NaCl
D)
H2O
15)
What does the formula C6H12O6 mean?
15)
A)
The molecular weight is 24.
B)
The substance is a colloid.
C)
There are 6 calcium, 12 hydrogen, and 6 oxygen atoms.
D)
There are, 6 carbon, 12 hydrogen, and 6 oxygen atoms.
16)
Select which reactions will usually be irreversible regarding chemical equilibrium in human
bodies.
16)
A)
H2O + CO2 to make H2CO3
B)
ADP + Pi to make ATP
C)
glucose molecules joined to make glycogen
D)
glucose to CO2 and H2O
17)
Which property of water is demonstrated when we sweat?
17)
A)
high heat of vaporization
B)
polar solvent properties
C)
high heat capacity
D)
reactivity
E)
cushioning
18)
Which of the following is an example of a suspension?
18)
A)
salt water
B)
rubbing alcohol
C)
blood
D)
cytoplasm
19)
The single most abundant protein in the body is ________.
19)
A)
collagen
B)
glucose
C)
DNA
D)
hemoglobin
20)
Select the correct statement about isotopes.
20)
A)
Isotopes occur only in the heavier elements.
B)
All the isotopes of an element are radioactive.
C)
Isotopes of the same element have the same atomic number but differ in their atomic masses.
D)
All the isotopes of an element have the same number of neutrons but differing numbers of
electrons.
21)
Which statement about enzymes is false?
21)
A)
Enzymes require contact with substrate in order to assume their active form.
B)
Enzymes may use coenzymes derived from vitamins or cofactors from meta llic elements.
C)
Enzymes may be damaged by high temperature.
D)
Enzymes have the ability to accelerate reactions as much as a billion-fold.
22)
Which of the following statements is false?
22)
A)
When the hydrogen ion concentration decreases, the hydroxyl ion concentration also
decreases.
B)
The pH of blood is slightly basic.
C)
When acids and bases are mixed, they react with each other to form water and a salt.
D)
The more hydrogen ions in a solution, the more acidic the solution.
23)
The basic structural material of the body consists of ________.
23)
A)
Nucleic acids.
B)
Lipids.
C)
Carbohydrates
D)
Proteins.
24)
What is a dipole?
24)
A)
an organic molecule
B)
a type of reaction
C)
a polar molecule
D)
a type of bond
25)
In a DNA molecule, the phosphate serves ________.
25)
A)
to bind the sugars to their bases
B)
to hold the molecular backbone together
C)
as nucleotides
D)
as a code
26)
Which of the following is the major positive ion outside cells?
26)
A)
potassium
B)
magnesium
C)
hydrogen
D)
sodium
27)
27)
A)
a weak acid
B)
a bicarbonate ion
C)
common in the liver
D)
a proton donor
28)
In general, the lipids that we refer to as oils have ________.
28)
A)
a high water content
B)
long fatty acid chains
C)
a high degree of unsaturated bonds
D)
a high degree of saturated bonds
29)
If atom X has an atomic number of 74 it would have which of the following?
29)
A)
37 electrons
B)
37 protons and 37 neutrons
C)
74 protons
D)
37 protons and 37 electrons
30)
Amino acids joining together to make a peptide is a good example of a(n) ________ reaction.
30)
A)
decomposition
B)
reversible
C)
synthesis
D)
exchange
31)
Salts are alw ays ________.
31)
A)
hydrogen bonded
B)
ionic compounds
C)
double covalent compounds
D)
single covalent compounds
32)
The four elements that make up about 96% of body matter are ________.
32)
A)
carbon, oxygen, hydrogen, nitrogen
B)
nitrogen, hydrogen, calcium, sodium
C)
sodium, potassium, hydrogen, oxygen
D)
carbon, oxygen, phosphorus, calcium
33)
The genetic information is coded in DNA by the ________.
33)
A)
regular alteration of sugar and phosphate molecules
B)
arrangement of the histones
C)
three-dimensional structure of the double helix
D)
sequence of the nucleotides
34)
A chemical reaction in which bonds are broken is usually associated with ________.
34)
A)
a synthesis
B)
forming a larger molecule
C)
the release of energy
D)
the consumption of energy
35)
Which bonds often bind different parts of a molecule into a specific three-dimensional shape?
35)
A)
Oxygen
B)
Hydrogen
C)
Carbon
D)
Amino acid
36)
Sucrose is a ________.
36)
A)
triglyceride
B)
disaccharide
C)
polysaccharide
D)
monosaccharide
37)
Which of the following elements is necessary for proper conduction of nervous impulses?
37)
A)
Na
B)
I
C)
Fe
D)
P
38)
What does CH4 mean?
38)
A)
This was involved in a redox reaction.
B)
There is one carbon and four hydrogen atoms.
C)
There are four carbon and four hydrogen atoms.
D)
This is an inorganic molecule.
39)
The numbers listed represent the number of electrons in the first, second, and third energy levels,
respectively. On this basis, which of the following is an unstable or reactive atom?
39)
A)
2, 8
B)
2
C)
2, 8, 1
D)
2, 8, 8
40)
Which of the following is not a role of molecular chaperonins?
40)
A)
promote the breakdown of damaged or denatured proteins
B)
aid the desired folding and association process of polypeptides
C)
act as a platform for assembling primary protein structure
D)
help to translocate proteins and certain metal ions across cell membranes
E)
prevent accidental, premature, or incorrect folding of polypeptide chains
41)
Which of the following statements is false?
41)
A)
Larger particles move faster than smaller ones and thus collide more frequently and more
forcefully.
B)
Catalysts increase the rate of chemical reactions, sometimes while undergoing reversible
changes in shape.
C)
Chemical reactions progress at a faster rate when the reacting particles are present in higher
numbers.
D)
Chemical reactions proceed more quickly at higher temperatures.
42)
The chemical symbol OO means ________.
42)
A)
the atoms are double bonded
B)
this is an ionic bond with two shared electrons
C)
zero equals zero
D)
both atoms are bonded and have zero electrons in the outer orbit
43)
31) You notice that you cannot read your book through a test tube of patient fluid held against the
print, making it so blurred as to be unreadable. There is no precipitant in the bottom of the beaker,
though it has been sitting for several days in a rack. What type of liquid is this?
43)
A)
suspension
B)
colloid
C)
mixture
D)
solution
44)
Atom X has 17 protons. How many electrons are in its valence shell?
44)
A)
10
B)
5
C)
7
D)
3
45)
What happens in redox reactions?
45)
A)
the organic substance that loses hydrogen is usually reduced
B)
the electron acceptor is oxidized
C)
the reaction is uniformly reversible
D)
both decomposition and electron exchange occur
46)
Which of the following is not true of proteins?
46)
A)
They have both functional and structural roles in the body..
B)
They appear to be the molecular carriers of coded hereditary information.
C)
Their function depends on their three-dim ensional shape.
D)
They may be denatured or coagulated by heat or acidity.
47)
What level of protein synthesis is represented by the coiling of the protein chain backbone into an
alpha helix?
47)
A)
primary structure
B)
secondary structure
C)
quaternary structure
D)
tertiary structure
48)
Which of the following does NOT describe enzymes?
48)
A)
Some enzymes are purely protein.
B)
Each enzyme is chemically specific.
C)
Some enzymes are protein plus a cofactor.
D)
Enzymes work by raising the energy of activation.
49)
Name at least four things you know about enzymes.
49)
50)
Functional protein
50)
51)
Which metals have a toxic effect on the body?
51)
52)
A chemical bond never occurs between components of a mixture. Discuss this.
52)
53)
Molecules such as methane that are made of atoms that share electrons have ________
bonds.
53)
54)
AB
A + B is an example of a(n) ________ reaction.
54)
55)
Tertiary (protein) structure
55)
56)
What type of chemical bond can form between an element with 11 protons and an element
with 17 protons?
56)
57)
What advantages does ATP have in being the energy currency molecule?
57)
58)
What happens when globular proteins are denatured?
58)
59)
All chemical reactions are theoretically reversible. Comment on this statement.
59)
Figure 2.2
60)
Hydrogen bonds
60)
61)
A holoenzyme is composed of an apoenzyme and a(n) ________.
61)
Figure 2.2
62)
Deoxyribose sugar.
62)
63)
Describe the factors that affect chemical reaction rates.
63)
64)
Explain the difference between potential and kinetic energy.
64)
Figure 2.2
65)
Guanine
65)
Figure 2.1
66)
Polymer
66)
67)
How many phosphates would AMP have attached to it?
67)
68)
In a DNA molecule, guanine would connect to ________.
68)
69)
An amino acid may act as a proton acceptor or donor. Explain.
69)
70)
Protons and electrons exist in every atom nucleus except hydrogen. Is this statement true
or false and why?
70)
71)
The atomic number is eq ual to the number of _______ _.
71)
Figure 2.1
72)
Lipid
72)
73)
Are all chemical reactions reversible? If not, why aren't they all reversible?
73)
Figure 2.1
74)
Monosaccharide
74)
Figure 2.2
75)
Phosphate
75)
76)
What properties does water have that make it a very versatile fluid?
76)
77)
What does the polar end of a phospholipid contain?
77)
78)
If all protons, electrons, and neutrons are alike, regardless of the atom considered, what
determines the unique properties of each element?
78)
79)
In the compound H2CO3, what do the numbers 2 and 3 represent?
79)
80)
Hydrogen bonds are more like a type of weak ________ than true bonds.
80)
81)
How can phospholipids form a film when mixed in water?
81)
82)
The ________ molecule directly provides energy for cellular work.
82)
83)
An atom with three electrons wo uld have a valence of ________.
83)
Figure 2.1
84)
Nucleotide
84)
85)
Weak acids a nd bases make good ________.
85)
86)
________ have a bitter taste, feel slippery, and are proton acceptors.
86)
87)
What is the major difference between polar and nonpolar covalent bonds?
87)
88)
When a set of electrodes connected to a light bulb is placed in a solution of dextrose and a
current is applied, the light bulb does not light up. When the same unit is placed in HCl, it
does. Why?
88)
89)
Starch is the stored carbohydrate in plants, while ________ is the stored carbohydrate in
animals.
89)
90)
Explain why chemical reactions in the body are often irreversible.
90)
91)
Polysaccharide.
91)
Figure 2.2
92)
Thymine
92)
93)
Current information suggests that omega-3 fatty acids decrease the risk of heart disease.
93)
94)
Buffers resist abrupt and large changes in the pH of the body by releasing or binding ions.
94)
95)
Glucose is an example of a monosaccharide.
95)
96)
Isotopes differ from each other only in the number of electrons the atom contains.
96)
97)
Chemical properties are determined primarily by neutrons.
97)
98)
The fact that no chemical bonding occurs between the components of a mixture is the chief
difference between mixtures and compounds.
98)
99)
All organic compounds contain carbon.
99)
100)
A chemical bond is an energy relationship between outer electrons and neighboring atoms.
100)
101)
Hydrogen bonds are too weak to bind atoms together to form molecules but are important
intramolecular bonds.
101)
102)
The pH of body fluids must remain fairly constant for the body to maintain homeostasis.
102)
103)
A dipeptide can be broken into two amino acids by dehydration synthesis.
103)
104)
The atomic weight is only an average of relative weights of an atom and its isotopes, and it may
vary from the weight of a specific isotope.
104)
105)
The acidity of a solution reflects the free hydrogen ions in the solution
105)
106)
Lipids are a poor source of stored energy.
106)
107)
Glycogen, the storage form of glucose, is primarily stored in muscle tissue only.
107)
108)
The lower the pH, the higher the hydrogen ion concentration.
108)
109)
Mixtures are combinations of elements or compounds that are physically blended together but are
not bound by chemical bonds.
109)
110)
Covalent bonds are generally less stable than ionic bonds.
110)
111)
A charged particle is generally called an ion or electrolyte.
111)
112)
About 60% to 80% of the volume of most living cells consists of organic compounds.
112)
113)
It is the difference in the R group that makes each amino acid chemically unique.
113)
matter.
114)
115)
Heterogeneous, will settle.
A)
Suspensions
completely lost or gained by the atoms
involved.
116)
117)
Blood.
A)
Mixture
Match the following:
118)
Heterogeneous, will not settle.
A)
Colloids
119)
Number of protons in an atom
A)
Atomic number
120)
Water.
A)
Compound
mass.
121)
neutrons in an atom
122)
the electromagnetic spectrum.
123)
unequally.
124)
gravity.
125)
126)
Carbon.
A)
Element
Match the following particles to the correct description:
retains its properties.
127)
128)
Dry ice (frozen carbon dioxide).
A)
Compound
different parts of the same molecule
together into a three-dimensional
structure.
129)
loss of an electron.
130)
131)
Legs moving the pedals of a bicycle.
A)
Mechanical energy
pounds on Earth would be lighter on
the moon and heavier on Jupiter, his
________ would not be different.
132)
name
133)
134)
Neutral subatomic particle.
A)
Neutron
Match the following chemical bonds to the correct description:
equally.
135)
136)
Will not scatter light.
137)
Homogeneous, will not settle.
A)
Solutions
particles along a conductor, or the
flow of ions across a membrane.
138)
still retains its properties.
139)
energy is released to do cellular work.
140)
141)
Mrs. Mulligan goes to her dentist and, after having a couple of cavities filled, her dentist strongly suggests that
she reduce her intake of sodas and increase her intake of calcium phosphates in the foods she eats. Why?
142)
A 65-year-old patient came to the emergency room with complaints of severe heartburn unrelieved by taking a
"large handful" of antacids. Would you expect the pH to be high or low? Explain why.
143)
How can DNA be used to "fingerprint" a suspect in a crime?
144)
Although his cholesterol levels were not high, Mr. Martinez read that cholesterol was bad for his health, so he
eliminated all foods and food products containing this molecule. He later found that his cholesterol level
dropped only 20%. Why did it not drop more?
145)
Brenda is a 26 -year-old female who is being discharged from the hospital after a vaginal delivery of an
8-pound healthy infant. Brenda is instructed by the nurse to eat a die t high in fiber and to drink 8 glasses of
water per day to prevent constipation. Explain the role of fiber and water to promote defecation.
146)
A 23-year-old male was riding his road bike in 100-degree heat, when he suddenly became nauseated and
weak. He called 911 from his cell phone. When the ambulance came, the paramedics started intravenous
therapy for severe dehydration. Explain the critical role of water to maintain homeostasis.
147)
Why is it possible for us to drink a solution that contains a mixture of equal concentration of a strong acid and a
strong base, either of which, separately, would be very caustic?
Answer Key
1)
D
2)
A
3)
B
4)
A
5)
B
6)
D
7)
B
8)
A
9)
B
10)
C
11)
D
12)
B
13)
C
14)
A
15)
D
16)
D
17)
A
18)
C
19)
A
20)
C
21)
A
22)
A
23)
D
24)
C
25)
B
26)
D
27)
B
28)
C
29)
C
30)
C
31)
B
32)
A
33)
D
34)
C
35)
B
36)
B
37)
A
38)
B
39)
C
40)
C
41)
A
42)
A
43)
B
44)
C
45)
D
46)
B
47)
B
48)
D
31
49)
1. They are proteins.
50)
B
51)
heavy
52)
Mixtures come in three forms–solutions, colloids, and suspensions. Components of these mixtures always retain their
53)
covalent
54)
decomposition
55)
B
56)
ionic
57)
Its energy is easy to capture and store; it releases just the right amount of energy for the cell's needs so it is protected
58)
The active sites are destroyed.
59)
reversible. Some would require an enormous amount of energy to reverse. In the simple reaction Na + Cl
NaCl the
60)
A
61)
cofactor
62)
B
63)
Temperature increases kinetic energy and therefore the force of molecular collisions. Particle size: smaller particles
64)
Potential energy is inactive stored energy that has potential to do work. Kinetic energy is energy in action.
65)
E
66)
C
67)
one
68)
cytosine
69)
Amino acids have two componentsa base group (proton acceptor) and an organic acid part (a proton donor). Some
71)
protons (and electrons)
72)
D
73)
All chemical reactions are theoretically reversible, but only if the products are not consumed.
74)
A
75)
C
76)
High heat capacity, high heat of vaporization, polarity and solvent properties, reactivity, and cushioning.
77)
a phosphorus-containing group
78)
Atoms of different elements are composed of different numbers of protons, electrons, and neutrons.
79)
The 2 indicates that there are two hydrogen atoms in the compound and the 3 indicates that there are three oxygen
Answer Key
80)
attraction
81)
Phospholipids have both polar and nonpolar ends. The polar end interacts with water, leaving the nonpolar end
82)
ATP
83)
one
84)
E
85)
buffers
86)
Bases
87)
Polar bonds have an unequal sharing of electrons resulting in a slight negative charge at one end of the molecule and a
88)
HCl ionizes to form current-conducting electrolytes. Dextrose does not ionize, and therefore does not conduct current.
89)
glycogen
90)
Chemical reactions that release energy cannot be reversed unless energy is put back into the system. Also, some
91)
C
92)
D
114)
A
115)
A
116)
A
117)
A
118)
A
119)
A
120)
A
121)
A
122)
A
123)
A
124)
A
33
125)
A
126)
A
127)
A
128)
A
129)
A
130)
A
131)
A
132)
A
133)
A
134)
A
135)
A
136)
A
137)
A
138)
A
139)
A
140)
A
141)
Sodas are strong acids that can reduce bone and tooth salts. Calcium phosphate makes teeth hard and therefore more
142)
You would expect a high pH. Taking antacids will neutralize the acidic stomach. Taking a "handful" of antacids can
143)
The DNA of a person is unique to that individual. By obtaining the DNA from nucleated cells from the crime scene
144)
Cholesterol is produced by the liver, in addition to being ingested in foods.
145)
Cellulose is a polysaccharide found in all plant products that adds bulk to the diet to promote feces through the colon.
146)
Water is the most abundant and important inorganic compound in living material. It makes up 60% to 80% of the
147)
When an acid and base of equal strength are mixed, they undergo a displacement reaction to form a water and a salt.