Transcript ANSWERS to PRACTICE EXAM for BCOR 011

Name ____________________
BCOR 011 Vayda/Stratton
Sept 14, 2005
PRACTICE EXAM QUESTIONS
Lectures 1, 2 & 3 (Bonding & Functional Groups, Water, pH & Hydrophobicity, Carbohydrates, Lipids,
Nucleic Acids &n Proteins, Cell Tour)
NOTE: MEMBRANE STRUCTURE AND FUNCTION WILL BE ON THE EXAM
These are “dry-runs” for the Exams you will take. The questions here ARE exam questions from previous
years (that’s why the jokes are so out of date). You will see questions similar to these on Sept 23 (with fresher
jokes).
Section I. MULTIPLE, Multiple Choice.
Rarely is there just one right answer in life. These questions are designed to explore the different characteristics of
individual things, processes or properties. Practice looking for ALL possible characteristics of an item while you are
studying your notes.
-Indicate all of the answers below that correctly relate to the questions in bold type. Note: there is frequently more
than one right answer! Sometimes there IS only one correct choice, other times none of the choices are correct, or
all may be correct. Think of this as a type of “true-false” choice for each possible answer to the question. When you
fill out the “bubble” answer sheet column 1 will be “true”, column 2 will be ”false”. On the the practice exam
below, you have 200 answer choices: so each choice is worth 0.5 pt; that is, if you say it is correct and it is, you get 0.5
pt; if you don’t say it is correct and it is, you lose 0.5 pt, etc. We the actual exam will probably be shorter (have less
answer choices, like 150), so each choice will be worth more (like 0.67 pt). You only have 50 min for the 9/23 exam.
A. The structure at right:
1) is a -sheet (beta)
2) is a base pair
3) is a micelle
3
4) is a starch grain
5) is an polysaccharide
B. The tertiary structure of a protein is:
6) the overall 3-D structure of the protein.
6
7) dictated by interactions of amino acid R-groups with one another.
8) dictated by interactions of the N-terminus with the C-terminus of the polypeptide.
7
9) influenced by the presence of disulfide bonds.
9
10) influenced by hydrophobic interactions.
10
11) the interaction of two or more polypeptide chains to form a protein complex.
12) the interaction of individual amino acids with one another to form a polypeptide.
13
13) dictated by how the surfaces of secondary structures interact with one another.
C. If the pH of a cytoplasmic compartment falls from 7.0 to 6.0 then:
14) the gloves must fit
15
15) the amount of H+ (hydronium) ions has increased
16) the amount of -OH (hydroxide) ions has increased
18
17) an acid with a pKa of 4.2 will lose its negative charge
18) a base with a pKb of 6.8 will become positively charged
19) phosphate functional groups will become positively charged
D. Which of the following biologically-important linkages are the result of condensation/dehydration reactions:
20) peptide bonds
21) ester linkages
20
22) phosphodiester bond
21
23) James Bond
22
24) hydrogen bonds
25) Van der Waal’s interactions
26
26) Glycosidic bonds
E. Covalent bonds:
27) are formed when two atoms share electrons.
28) enable atoms to form molecules with stable, precise spatial configurations
27 29) give the molecule a positive charge at high pH
30) can be purchased through your stockbroker.
28
F. Atoms interact to attain chemical stability by:
31) sharing electrons to form covalent bonds
32) sharing the Oval Office
31
33) “stealing” electrons to complete a stable outer electron shell
33
34) forming micelles
35) sharing intimate secrets with Linda Tripp
G. Chiral carbons:
36) are found in carbohydrate polymers
37) are found in amino acids
36
38) are found in polypeptides
39) were found at Rockingham
37
40) are found in saturated fatty acids
38
41) are found in water
42
42) are found in DNA
43
43) have 4 different functional groups attached to them
44) cannot interact with water
H. Amino acids:
45) as monomers, can be expected to be ions at pH 7.0
45
46) with non-polar “R” groups include alanine, valine and leucine.
46
47) can be joined in linear polymers to form polypeptides.
47
48) were allegedly used by Nicole and Faye Resnick
49) with alcohols for “R” groups include threonine and serine
49
I.
51
53
54
55
56
58
59
60
61
62
Intracellular membrane-bound organelles:
50) Are typically observed in Prokaryotes
51) Comprise distinct compartments within the cytoplasm
52) Are the cell’s lock boxes
53) Include “mitochondria”
54) are typically observed in Eukaryotes
55) include the “Golgi Apparatus”
56) include the “endoplasmic reticulum”
57) include “ribosomes”
58) include “nuclei” (plural of “nucleus”)
59) contain “phospholipids” in their membranes
60) allow different functions to occur in a cell at the same time
61) allow different microcompartments within the cell to have distinct internal pH’s
62) allow the cell to maximize effective surface area
J. Water has a tendency to :
63 63) Form hydrogen bonds with polar molecules
66 64) Form hydrogen bonds with non-polar molecules
68 65) Form four oxygen bonds with carbon– molecules +
66) ionize and form the charged species OH and H
67) Form hydrogen bonds with hydrocarbon chains (R-CH2-CH2-CH2-CH3)
68) Form hydrogen bonds with amino groups (R-NH2)
69) Bomb Iraq
70) Let the weapons inspectors do their job
K. A Carbon atom always makes this number of covalent bonds:
71) one
73 72) two
73) four
74) eight
L. Eukaryotic cells differ from prokaryotic cells in that eukaryotic cells:
75) are typically much larger than prokaryotic cells
75
76) contain internal membranes and membrane bound organelles whereas
76
prokaryotic cells typically do not
77))
store
their
genetic
information in the DNA whereas prokaryotic cells use RNA to
78
store genetic information
78) have nuclei whereas prokaryotic cells do not
79) have viruses whereas prokaryotic cells do not
M.
80
Which of the following is a membrane-bound organelle?
80) ribosome
81) nucleus
82) triglyceride
83) microtubule
N. A covalent bond between a carbon and a hydrogen atom is considered:
84) nonpolar
84 85) polar
86) ionic
87) ironic
88) romantic
O. A solution with a pH of 5 :
89) has a hydrogen ion concentration of 1x10-9M
91
90) has a water concentration of 5 M
91) has a hydrogen ion concentration of 0.00001M
92) cannot form hydrogen bonds
P. A carboxylic acid group with a pKa of 5.5:
93) Will be ionized at pH 7.0
93 94) Will be uncharged at pH 7.0
95 95) Will be uncharged at pH 4.0
98 96) Will be uncharged at pH 8.8
99 97) Will bear a negative charge in a solution that has 1x10-10 M –OH ions
98) Can form a condensation reaction with an alcohol group to form an ester bond
99) Is hydrophilic
Q. Which of the following components are found in prokaryotes (bacteria and cyanobacteria)?
100) plasma membrane
102) nucleus
100
103) endoplasmic reticulum
104) golgi apparatus
105
105) ribosomes
106
106) DNA
107) bloody gloves
108) mitochondria
109) chloroplasts
110) lysosomes
111) Bruno Magli shoes
R. Carbohydrate polymers are polar molecules which tend to:
112) be insoluble in water.
113) hydrogen bond with themselves rather than water.
112
114) form micelles which are great for cleaning greasy dishes.
115) be slimy, gooey or gelatinous when forced to be fully hydrated by water.
113
116) serve as recognition markers on external surfaces of membrane proteins.
115
117) hydrolyze peptide bonds.
116
S. Which of the following components are usually found in DNA:
118) phosphatidyl Choline
121
119) Glutamic acid
124
120) the preservative EDTA
121) Adenosine monophosphate
122) phosphatidyl Inositol
123) Threonine
124) deoxyRibose
T. Phospholipids tend to:
125) form aromatic rings.
126) be solids at room temperature if comprised of unsaturated fatty acids.
129
127) form cholesterol.
128) be hydrolyzed to cholesterol and wax.
130
129) form bilayers and vesicles.
130) bear a negative charge at pH 7.0.
U. Which of the following structures represents a monosaccharide?
131) C12H22O11
133) HO – C = O
|
132
H – C – OH
|
H – C – OH
|
H
132)
134)
V. An alpha helix ( a-helix ) :
135) Is a “primary structure” that a polypeptide can adopt
136
136) Is formed when one polar peptide bond hydrogen bonds with another peptide bond
further down the chain
137) is held together by disulfide bonds
138) Is the covalent bonding arrangement that holds two polypeptides into a quaternary
structure
139) Is a secondary structure of DNA and other polynucleotide chains
W. Which of the following are considered “hydrophobic” amino acids with “hydrophobic”
R groups
1.
141
140) glucose
144) serine
148) palmitic acid
142
141) leucine
145) valine
142)
phenylalanine
146) glutamine
145
143) adenine
147) lysine
X. The molecule below :
149) is the L form of an amino acid
150
150) is likely to be a liquid oil
154
151) is a pentose
155
152) is likely to bear a negative (-) charge at pH 7.0
153) is a trisaccharide
156
154) is comprised of one or more unsaturated fatty acids
155) is hydrophobic
156) was found on Monica Lewinski’s dress Among other things
Note: will never take off for a “joke” answer
Y. The SECONDARY STRUCTURE of DEOXYRIBONUCLEIC ACID (DNA) polymer:
157) Is formed by linking ATP mononucleotides together
158) Is a double-helix of anti-parallel strands
158
159) Is an alpha (a) helix of two parallel strands
161
160) Is a beta () helix of two anti-parallel strands
162
161) Is stabilized by precise hydrogen bonding of complementary “bases” trapped in a
165
non-polar microenvironment; A with T, G with C
162) Is driven by the need for hydrophobic bases to stack on top of one another
163) Is driven by the insatiable desire for Bill Clinton to stack… (let’s not go there)
164) Is driven by the political motives of Kenneth Starr
165) Has the negatively (-) charged phosphate groups on the outside, exposed to water
166) is maintained “fluid” by the presence of unsaturated fatty acids in the polymer
Z. The monomers which make up a polypeptide are:
167) held together by phosphodiester bonds
168) chiral
168
169) nitrogenous bases
172
170) unsaturated
171) nucleotides
172) amino acids
173) monosaccharides
174) interns
AA. Cellulose and Amylose (starch):
175) both contain the exact complement of amino acids but arranged in different orders
176) are both polymers of D-glucose but monomers of one are bound together by a1-4
176
glycosidic linkages whereas the other is bound together by 1-4 glycosidic
178
linkages
177) are both polysaccarides, but one is hydrophobic and the other is hydrophilic
178) are polymers comprised of glucose but have very different 3-D shapes
179) are amphipathic molecules
180) are buffers which can bind ATP
BB. Which of the following amino acids has a hydrophilic R-group ?
181) isoleucine
182) threonine
183) arginine
182
183
184
184) glutamic acid
CC. Familiarity with the properties of water is important to understand:
185) Why polymers adopt the secondary and tertiary structures they do
186) How soap works
187) What chirality is
185 188) What a “lock box” is
186 189) Why we need a tax cut (didn’t Reagan try this already?)
190 190) Why some hydronium (H+) ions and hydroxide (-OH) ions are always present for reactions in
water
191
191)
Why
hydrophilic polymers tend to hydrogen bond with themselves rather than water
194
192) Who this Chad guy is
193) How Chad got pregnant.
194) Why membranes form in water
195) Why carbon atoms can form covalent bonds with 4 other atoms
DD. A molecule that is Chiral has :
196) an unshared pair of electrons
199 197) a pH of 7
200 198) hydrophobic character
199) a left-handed and right-handed form
200) at least one carbon with four different functional groups bonded to it
2. The fluid mosaic model of membranes predicts that:
B
C
E
a) O.J. did it.
b) phospholipids are free to move laterally in membranes.
c) proteins are free to move laterally in membranes.
d) fluids are free to pass through membranes but solid particles cannot.
e) polypeptides are embedded in a sea of phospholipids.
f) polymers of a-D-glucose are soluble in water whereas polymers of -D-glucose are not.