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Name:_____________
Chem 150 Practice Exam #3
Exam 3
Directions:
1. Do not open the exam until you are told to do so.
2. Select only ONE choice for each problem and blacken or fill in the choice with a
pencil (NOT ink pen). Selecting more than one choices or no selection for a problem
will be counted wrong.
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CHEM 150, EXAM 3:
May 6, ’05
Name:__________________
Ch. 8 Lipids:
1. In which solvent would lipids be most soluble? a
a. hexane
b. water
c. methyl alcohol
d. ethyl alcohol
2. Inspect the molecules below and answer the questions that refer to these molecules. Molecules
like these are classified as _______ . b
O
A
HO
B
HO
C
HO
C
O
H
C
H
O
H
C
a.
b.
c.
d.
e.
triglycerides
fatty acids
waxes
phospholipids
none of the above
H
O
D
HO
H
H
C
3. Molecule “B” in question #2 above can be referred to as _____ . d
a. stearic acid
b. lauric acid c. Oleic acid d. -3 fatty acid
e. none of the above
4. Refer to question #2. Molecules B, C and D are said to be ________ . b
a. saturated b. unsaturated
c. completely hydrophobic d. completely hydrophilic
5. Because of the properties in portion A and portion B, the molecule below is said to have ______
properties. d
O
a. hydrophobic
c. hydrophilic
HO C
A
b. lipophobic
d. amphipathic
B
6. The structure CH3(CH2)12CH2COOCH2(CH2)24CH3 is best classified as a _____, b
a. triglyceride
b. wax
c. steroid
d. phospholipid
e. none of the above
7. The steroid compound that is the source for the production of other steroid hormones is ____ . c
a. arachidonic acid
b. triglyceride
c. cholesterol
d. phospholipids
8. The steroid compound that is believed to be used for maintaining the correct degree of cell
membrane rigidity is ____ . d
a. arachidonic acid
b. triglyceride
c. sphingolipid
d. cholesterol
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3
Use the molecules in question #9 to answer questions # 9 – 11:
9. Which molecule is glycerophospholipid? Note: R’s represent long carbon chains. b
O
H C O C R
O
H C O C R'
H
A
H C O O
C R"
H
B
C
O
H C O C R
O
H C O C R'
H
OH
H C
H C
NH
O
C
R
H C O O
+
P O CH2CH2N(CH3)3
H
O-
H C O O
P O CH2CH2NH2
H
O-
a. A
b. B
c. C
d. none of
the above
10. Which molecule is a lipid called sphingomyelin. c
a. A b. B c. C d. none of the above
11. Which compounds form the cell membrane? d
a. A only
b. B only
c. C only
d. B and C only
e. none of the above
12. Which molecule makes up oil? (Use the A, B and C as your answer choices.) c
A
O
H
H C O C
O
H C O C
O
H
H C O C
O
H C O C
H C O O
C
H
H C O O
C
H
C
O
H C O C
O
H C O C
H
B
H C O O
C
H
13. Refer to question #12. Which molecule contains the fatty acyl groups of palmitic acid, stearic
acid, and myristic acid? b
a. A only
b. B only
c. C only
d. both A and B
e. none of the above
14. The effect of the hydrogenation of oils is to _____. a
a. remove double bonds, increasing the degree of saturation.
b. cause the oils to remain as liquids, increasing the C=C bonds.
c. make the oils boil at a lower temperature
d. make the oils oxidize
15. Shown below is the structure of estradiol. It belongs to what class of lipids? d
a.
b.
c.
d.
phospholipids
eicosanoids
triglycerides
steroids
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16. Estradiol is considered to be a __________ hormone. a
a. human female
b. human male
c. plant
d. potato hormone
17. Shown below is a picture of the lipid bilayer
of the cell membrane. The tails of the lipids face
each other because they are _____ . a
a. hydrophobic
c. amphipathic
18. This compound is a ______ . c
b. hydrophilic
d. amphoteric
a. glycerolphospholipid
c. glycolipid
b. sphingomyelin
d. triglyceride
19. What is the function of HDL? a
a. transport cholesterol and phospholipids from cells to liver.
b. transport cholesterol and phospholipids from liver to cells.
c. digest cholesterol and phospholipids in cells.
d. digest cholesterol and phospholipids in liver.
____
Ch. 12 Carbohydrates:
20. Which is the structure of glucose? d
O
O
OH
C
O
CH2OH
H
HO
a).
H
H
OH
H
OH
OH
b).
C
C O
HO
H
H
OH
H
OH
c).
H
H
H
OH
OH
OH
CH2OH
CH2OH
CH2OH
C
H
H
HO
d).
H
H
H
OH
H
OH
OH
CH2OH
21. The monosaccharide below is a(n) _____ . b
O
C
H
H
H
H
a. purine
b. aldose
c. enantiomer
d. ketose
e. glycolysis
OH
OH
OH
CH2OH
22. Which molecule contains the pyranose ring? a
HOCH2
HO
a).
HOH2C
O
OH
O
HO
b).
CH2OH
c). none of the above
OH
OH
OH
HO
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23. Which molecule below is an aldohexose? a
O
H
C
O
H
HO
HO
H
a).
C
OH
H
H
OH
H
b).
C
C O
HO
H
c).
H
OH
H
OH
OH
HO
O
CH2OH
H
H
CH2OH
d).
H
OH
H
H
OH
OH
CH2OH
CH2OH
CH2OH
CH2OH
H
H
e). H
H
C O
OH
OH
OH
CH2OH
24. Molecules II and IV are a pair of ________ . a
O
C
H
H
H
O
OH
OH
C
H
HO
CH2OH
H
O
OH
H
a. enantiomers
d. anomers
H
HO
HO
CH2OH
II
I
C
O
H
H
HO
H
CH2OH
III
b. cis-trans isomers
e. none of the above
C
H
H
OH
CH2OH
IV
c. identical molecules
25. Which is the structure of -D-glucose? c
CH2OH
O
HO
OH
O
O
OH
OH
HO
OH
B
A
a. A
b. B
C
OH
c. C
d. D
O
HO
OH
OH
HO
CH2OH
CH2OH
CH2OH
OH
HO
OH
OH
CH2OH
D
e. none of the above
26. Which is the structure of α-D-galactose? (Look up the structure on a sheet.) B
CH2OH
CH2OH
HO
O
OH
HO
O
OH
OH
OH
OH
OH
A
B
27. The structure of -D-ribose is shown below. Identify the anomeric carbon or hemiacetal carbon in -Dribose. a
HOH2C
O
OH
HO
OH
a. 1 only
b. 2 and 3
c. 3 and 4
d. 1, 2 and 3
e. 1, 2, 3, and 4
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28. If a molecule of sucrose is hydrolyzed (broken down to monosaccharides), what would be the
monosaccharides found in the products? (Note: Do not consider the - or -forms). c
a. two molecules of fructose
c. one glucose and one fructose
e. one fructose and one galactose
b. one lactose and one glucose
d. one galactose and one glucose
29. If a molecule of maltose is hydrolyzed, what would be the monosaccharides found in the
products? (Note: Do not consider the - or -forms). c
a. two molecules of fructose
c. two molecules of glucose
e. none of the above
b. one fructose and one galactose
d. one lactose and one glucose
30. If a molecule of lactose is hydrolyzed, what would be the monosaccharides found in the
products? (Note: Do not consider the - or -forms). a
a. one glucose and one galactose
c. one fructose and one galactose
e. none of the above
b. one maltose and one fructose
d. one fructose and one glucose
31. Olestra is composed of a disaccharide and several fatty acyl groups. What disaccharide is
contained in the Olestra molecule?
a. lactose
b. maltose
c. sucrose
d. cellobiose e. none of the above
32. Which molecule possesses the (14) glycosidic bond? b
HOCH2
O
HOCH2
OH
HOCH2
OH
HOCH2
O
O
a. A only
OH
A
b. B only
OH
O
HO
OH
OH
OH
OH
OH
HO
O
O
OH
B
c. both A and B
Use the picture below to answer questions # 33 - 34.
CH2OH
33. The molecule shown to the right can be classified as a(n)
___ . b
a. monosaccharide b. disaccharide c. polysaccharide
d. dipeptide
e. none of the above
OH
O
O
HO
34. The glycosidic bond present on this molecule is _____ . c
a. (14)
b. (14)
c. (16)
d. (12)
e. 16
CH2
OH
O
OH
OH
HO
OH
35. What type of polysaccharide is shown below? a
HOCH2
HOCH2
HOCH2
OH
OH
OH
O
O
O
O
O
O
O
OH
OH
OH
a.
b.
c.
d.
e.
amylose
cellulose
amylopectin
glycogen
starch
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36. What is the biological role of amylopectin? c
a. provide structural rigidity in plants
c. provide energy or energy storage in plants
e. form bile salts
b. provide structural rigidity in animals
d. provide energy or energy storage in animals
37. What is the biological role of glycogen? d
a. provide structural rigidity in plants
c. provide energy or energy storage in plants
e. form cell membranes
b. provide structural rigidity in animals
d. provide energy or energy storage in animals
38. What polysaccharide provides structural protection to insects or crustaceans? e
a. Cellulose
b. amylose
c. amylopectin
d. glycogen
e. chitin
39. How is the structure of cellulose different from that of amylose? b
a. Cellulose has α(14) glysidic bond, but amylose has (14) glysidic bond.
b. Cellulose has (14) glysidic bond, but amylose has α(14) glysidic bond.
c. Cellulose has no branches, but amylose has brances.
d. Cellulose has branches, but amylose has no brances.
40. How is the structure of glycogen different from that of amylopectin? c
a. Glycogen has (14) and α(16) glycosidic bonds, but amylopectin has (14) bonds.
b. Amylopectin has more frequency of branching than glycogen.
c. Glycogen has more frequency of branching than amylopectin.
d. Glycogen has α(14) and α(16) glycosidic bonds, but amylopectin has (14) bonds.
41. What type of glycosidic bond is present on this polysaccharide found in certain types of lichens?
d
O
CH2
O
O
OH
CH2
O
HO
OH
OH
HO
O
a.
b.
c.
d.
e.
α(14)
(14)
α(16)
(16)
none of the above
OH
Ch. 13: Amino acids
51. The side chain of the amino acid
phenylalanine is shown here. The side chain
is classified as _____. a
a. nonpolar
b. polar-acidic
-H2C
c. polar-basic
d. polar-neutral
52. The side chain of the amino acid histidine is
shown here. The side chain is classified as
_____. c
a. nonpolar
H
N
b. polar-acidic
+
c. polar-basic
N
-H 2C
H d. polar-neutral
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54. Shown here is the amino acid alanine at a pH
of _____. b
53. Shown here is the amino acid alanine at a pH
of _____. c
H
O
+
H3N C C
CH3
O-
a.
b.
c.
d.
1
14
neutral pH
both (a) and (c)
H
O
H2N C C
CH3
O-
a.
b.
c.
d.
1
14
neutral pH
both (a) and (c)
55. The side chains of which pair of amino acids can form a salt bridge? Note: Look up the amino
acid structure sheet. c
a. Glycine and Aspartic acid
b. Glutamic acid and Aspartic acid
c. Lysine and Glutamic acid
d. Alanine and Leucine
e. none of the above
56. A zwitterion is an _____. c
a. ion that is polar acidic.
b. ion that is polar basic.
c. ion that has both positive and negative charge.
d. ion that is polar neutral.
Use this molecule to answer questions #57 – 59:
H2N
H
O
H
H
O
H
H
O
H
H
O
H
H
O
H
H
O
C
C
N
C
C
N
C
C
N
C
C
N
C
C
N
C
C
H
CH2
H
CH2
CH2
O
CH2
CH2
C
OH
O-
OH
A
CH2
NH3+
57. This molecule can be classified as a(n) _____ . c
a. polysaccharide
b. polypeptide
c. hexapeptide
d. protein
58. What is the amino acid
sequence of this molecule? b
a. Pro-Ser-Asp-Gly-Lys-Gly
b. Gly-Lys-Gly-Asp-Ser-Pro
c. Gly-Arg-Gly-Asp-Ser-Pro
d. Pro-Ser-Glu-Gly-Lys-Gly
e. none of the above
59. The N-terminus amino acid residue is ______ . b
a. Proline
b. Glycine
c. Lysine
d. Aspartate
60. The denaturing of a protein can
be caused by _____. d
a. heating
b. exposing to detergents
c. changing the pH
d. All of these can cause
denaturation
61. Which picture below best represents the structure of the
Hemoglobin molecule? Note: Each circle represents a
subunit. c
62. Enzymes are _____ . a
a. proteins
b. polysaccharides
c. lipids
63. Circle all the chiral carbon atoms on this molecule. This is
testing on the concept of chirality. e
a).
b).
c).
d).
8
9
d. inorganic compounds
e. coordination compounds
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CH3
N
2
1
9
3
7
O
C
10
O
CH3
4
6
O
5
O
C
11
17
16
15
a. 4 and 5
b. 4, 5, 9, and 11
c. 2, 3, 7, 9, and 11
d. 3, 4, 5, 6, 8 and 17
e. 3, 4, 5, and 7
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13
14
64. Evaluate this statement and see what level of protein structure it describes. “The polypeptide
chain has a number of bends and twists which result in compacting it into a ball-like unique threedimensional shape.” c
a. primary structure
d. quaternary structure
b. secondary structure
e. none of the above
c. tertiary structure
65. The α-helix and β-pleated sheet are both forms of the _____ structure of proteins. b
a. primary
b. secondary c. tertiary
d. quaternary
Use the picture below for questions # 66 - 69:
A
C
B
E
D
66. On the structure of the protein above, the non-covalent interaction labeled by arrow “A” is called
______ . d
a. salt bridge
b. hydrogen bond
c. disulfide bond
d. hydrophobic interaction
e. none of the above
67. On the structure of the protein above, the non-covalent interaction labeled by arrow “B” is called
______ . a
a. salt bridge
b. hydrogen bond
c. disulfide bond
d. hydrophobic interaction
e. none of the above
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68. Which arrow points to a region that has the
-sheet structure? d
a. A b. B c. C d. D e. E
70. What would happen to the non-covalent interaction
in the protein structure below if the Lysine side chain is
replaced with a Glutamic acid side chain (CH2CH2COO-)? c
69. Which arrow points to a region that has
the α-helical structure? e
a. A b. B c. C d. D e. E
71. On the picture below, what does Z
represent? a
y
x
a type of non-covalent interaction
Lysine
-CH2CH2H2CH2NH3+
II
_
O
z
NO "P" is formed
C CH2- Aspartic acid
O
a). The non-covalent interaction shown would remain
intact.
b). The protein structure would be broken down to
individual amino acids.
c). The ionic interaction would be broken and cause the
protein to lose its unique structure.
d). Hydrogen bond would be formed between the
-CH2CH2COO- and –OOCCH2- side chains, and the
protein structure would remain the same.
a. Z = enzyme
c. Z = products
b. Z = substrate
d. Z = inhibitor
____________________
72. What is the effect of X upon binding or
fitting into one of the pocket on Z in question
#71? c
a. stimulation of product formation (Product
formed faster).
b. has no effect.
c. inhibition of product formation.
d. X turns into product.
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