Download Fall 2009 Chem 306 Exam II KEY

Multiple Choice (3 pts each)
1. Which of the following contains a carboxyl functional group?
OH
O
a.
OH
H
O
O
O
b.
c.
O
OH
O
d.
O
2. The most common reactions of carboxylic acids or their derivatives involve
a. oxidation of the carboxyl group
b. substitution of the hydroxyl group
c. addition across the double bond between the carbon and the oxygen atoms.
d. replacement of the oxygen atoms in the carbonyl group.
e. More than one of these.
3. Of the following, which lists glycolic acid, ethanoic acid, phenol, and ethanol in order of increasing
acidity?
a. ethanol, phenol, ethanoic acid, glycolic acid
b. ethanol, phenol, glycolic acid, ethanoic acid
c. ethanol, ethanoic acid, phenol, glycolic acid
d. phenol, ethanol, glycolic acid, ethanoic acid
e. ethanol, ethanoic acid, glycolic acid, phenol
4. The sodium salt of a long chain carboxylic acid is called a
a. triglyceride
b. ester
c. soap
d. fatty acids
e. toothpaste
5. What is the IUPAC name of the molecule below?
O
O
a.
b.
c.
d.
e.
butyl pentanoate
pentyl butyrate
Helen
propyl pentanoate
pentyl pentanoate
6. What is the IUPAC name of the molecule shown?
O
N
H
a.
b.
c.
d.
e.
N – methylpropanamide
N – methylmethanamide
N – propylmethanamide
N - propyl amide
N – amidopropane
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7. Which of the following notations corresponds to the fatty acid with the highest melting point?
a. 18:0
b. 18:1
c. 18:2
d. 18:3
e. 18:4
8. What type of reaction is referred to in the phrase “saponified palm oil, coconut oil, and olive oil” in the
soap label shown below?
Honey, Lemon, and Oatmeal Soap
Contains saponified palm oil, coconut oil, and
olive oil, grapefruit seed extract, honey, oatmeal,
and essential oils of citronella, lemongrass,
and pink grapefruit..
a.
b.
c.
d.
e.
esterification
ester hydrolysis
reduction
oxidation
hydrogenation
9. Which of the following statements about naturally occurring fatty acids is false?
a. Nearly all of them contain an even number of carbon atoms.
b. Animal lipids are rich in saturated fatty acids and plant lipids are rich in unsaturated fatty
acids.
c. The cis isomer predominates in unsaturated fatty acids.
d. Arachadonic acid is considered to be a dietary essential fatty acid because it is needed to
make other important lipids in the body.
e. More than one of the above
10. Trans fatty acids are found in processed food as the result of which of the following chemical
processes?
a. hydrolysis
b. hydrogenation
c. condensation
d. dehydration
e. More than one of the above.
11. Salicylic acid is a(n)
a. Amino acid
b. β – hydroxy acid
c.  – hydroxy acid
d. Σ – hydroxy acid
e. strong acid
12. Which of the following is true about a detergent?
a. A detergent molecule is similar in structure to a soap molecule except that the anionic polar
head group of a detergent is a sulfate group instead of a carboxylate group.
b. Detergents do not form an insoluble solid with the magnesium and calcium ions found in tap
water.
c. A common detergent found in shampoos and hand-washing formulations is sodium lauryl
sulfate.
d. The mechanism of the cleaning action of detergents is the same as that for soaps.
e. All of the above are true.
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13. Ethyl benzoate has a pleasant odor. It is used in perfumery under the name essence de Niobe. It is
also component of some artificial fruit flavors. Which of the following is produced by the acid
catalyzed hydrolysis of ethyl benzoate?
a. ethanol and benzoic acid
b. ethanoic acid and benzyl alcohol
c. ethanol and phenol
d. ethanoic acid and phenol
e. None of the above.
14. The structure for ATP is shown below. Which of the bonds is a phosphoric anhydride bond?
a.
b.
c.
d.
a
b
c
d
15. Nylon and protein are both referred to as polyamides because
a. they are formed when an acid reacts with ammonia.
b. many amides react to form a polyamide.
c. they are formed when acid functional groups react with amine functional groups.
d. they are produced by reaction between an amide and an ester.
e. they produce amides when hydrolyzed.
16. Which of the following classes of biomolecules is best characterized as an aldehyde or ketone that
has more than one hydroxyl group?
a. Lipids
b. Carbohydrates
c. Proteins
d. Nucleic acids
e. None of the above.
17. Fructose can be classified as a(n)
a. aldopentose
b. aldoketose
c. aldohexose
d. ketopentose
e. ketohexose
18. Which carbon of a pentose determines if the pentose has the D or L configuration?
a. C – 1
b. C – 2
c. C – 3
d. C – 4
e. C – 5
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19. How many L stereoisomers of an aldotetrose can exist?
a. 2
b. 4
c. 8
d. 16
e. 32
20. When a monosaccharide forms a ring by interaction of one of its hydroxyl groups with its aldehyde
group, the new structure that is formed is referred to as a(n) ______________.
a. ester
b. ether
c. glycoside
d. acetal
e. hemiacetal
21. The acid hydrolysis of a lactose molecule yields
a. two glucose molecules
b. two galactose molecules
c. two fructose molecules
d. one galactose and one glucose molecule
e. one galactose and one fructose molecule
22. Morphine metabolites found in the urine are tested as morphine glycosides. This means that
a. the morphine is covalently bonded to the anomeric carbon of a sugar molecule.
b. the morphine molecule tastes sweet
c. there is an acetal link between the morphine molecule and a sugar molecule.
d. Both a and c are correct.
e. None of these
23. Which of the following is not a reducing sugar?
a.
b.
HO OH
H
H
OCH3
HOHO
O
HO
H
H
H
OH
H
H
OH
OH
d.
H
CH2OH
C O
H C OH
HO C H
H C OH
CH2OH
H
HO
H
HO
c.
e.
OH OH
HO
H
H OH
O
OH
H
HO
H
H
O
H
OH
H
HOH2C
H
OH
4
O
OH H
H
H
OH
OH
24. Which of the following does not consist of modified sugar molecules?
a. heparin.
b. hyaluronic acid
c. chondroitin
d. phospholipid
e. All of the above contain modified sugars
25. The enzyme invertase catalyzes the ____________ of _____________.
a. oxidation; sucrose
b. reduction; glucose
c. enediol formation; fructose
d. glycoside formation; sucrose
e. hydrolysis; sucrose
26. Which of the following statements best describes the substance represented by the structure below
(repeating segment of a larger structure)?
a. A polysaccharide known as the fibrous substance that provides structure in plants.
b. A polysaccharide associated with connective tissue including blood vessels, cartilage, and
tendons.
c. An energy-storage polysaccharide found plants that is fully digestible by humans.
d. An energy-storage polysaccharide found in animals.
27. Sugar alcohols such as sorbitol and mannitol are produced via the _________ of a monosaccharide
and are used as _________________.
a. reduction; sweetners
b. oxidation; emulsifiers
c. reduction; emulsifiers
d. oxidation; sweetners
e. esterification; emulsifiers
28. Which of the following polysaccharides cannot be digested by human enzymes?
a. amylase
b. glycogen
c. cellulose
d. amylopectin
e. none can be digested
29. Mutarotation is a process where
a. glucose undergoes reaction to form an equilibrium mixture of anomers.
b. glucose reacts with an alcohol forming a cyclic acetal.
c. the aldehyde group present in a sugar is converted to a hemiacetal.
d. two glucose molecules react to form a disaccharide.
e. glucose isomerizes to fructose
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30. A newspaper article characterizing research in the treatment of osteoarthritis of the knee described
the use of nutritional supplements as one approach. Which of the following modified sugars would
most likely be considered for use in this type of research?
a. glucitol
b. sodium gluconate
c. gluconic acid
d. glucosamine
e. glucopatellic acid
31. The bond connection the two monosaccharides in sucrose is a(n) ____________ linkage
a. β – 1,4 glycosidic
b.  – 1,4 glycosidic
c. 1,2 anomeric
d.  – 1,6 glycosidic
e. β – 1,4 glycosidic
32. Biomolecules are classified as lipids on the basis of
a. A common structure consisting of long hydrocarbon chains
b. The presence of many hydroxyl groups and at least one carbonyl group
c. The presence of carbon to carbon double bonds
d. The physical properties of odor, color, and melting point
e. The physical property of solubility in nonpolar solvents.
33. The molecule shown can be classified as a(n)
O
CH3(CH2) 28CH2 O
a.
b.
c.
d.
e.
C CH2(CH2)16CH3
steroid
eicosanoid
wax
glycerophospholipid
sphingolipid
34. Triglycerides are
a. simple esters of long chain alcohols and fatty acids
b. fatty acid triesters of glycerol
c. readily hydrolyzed into glycerol and three esters.
d. classified as phospholipids.
e. More than one of the above.
35. Glycolipids are similar in structure to sphingomyelins, except that the phosphate group has been
replaced by a(n)
a. choline derivative
b. carbohydrate
c. fatty acid
d. amino acid
e. nucleic acid
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36. The basic structure of cell membranes consists of
a. protein micelles with embedded phospholipids
b. protein bilayers with embedded phospholipids
c. one protein layer and one phospholipids layer
d. phospholipids micelles embedded with proteins
e. phospholipid bilayers embedded with proteins
37. The function of glycolipids in cell membranes is to
a. vary the fluidity of the membrane as needed.
b. mediate interaction between the cell and outside agents
c. provide channels for facilitated diffusion
d. provide energy for cell processes
e. act as local hormones
38. The molecule shown below can be classified as a(n)
a.
b.
c.
d.
e.
sphingolipid
phospholipid
glycolipid
both and c
both a and b.
39. Which of the following is true of all glycerophosholipids?
a. Their fatty acids are all saturated.
b. Their fatty acids are all unsaturated.
c. There is always a saturated fatty acid bound to carbon 2 of glycerol.
d. There is always an unsaturated fatty acid bound to carbon 2 of glycerol.
e. More than one of the above.
40. Which statement about eisosanoids is not correct?
a. The parent molecule, arachadonic acid, contains 20 carbon atoms.
b. Linolenic acid is a synthetic precursor to arachadonic acid
c. The eicosanoids include prostaglandins, thromboxanes, and leukotrienes.
d. Eicosanoids function as “local hormones”, acting as short-term chemical messengers
e. None of the above
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41. Which of the following is a prostaglandin?
a.
c.
b.
d.
c.
d.
.
42. Asprin prevents the synthesis of prostaglandins by
a. inhibiting COX1 and COX 2 (cycloxygenase) enzymes.
b. destroying the fatty acid synthetic precursors to prostaglandins.
c. Inhibiting enzymes that catalyze fatty acid oxidation
d. hydrolysis of ester links in the prostaglandin molecule
e. More than one of the above.
43. Which of the following is not an omega-3 fatty acid?
a. DHA (docosahexaenoic acid)
b. EPA (eicosapentaenoic acid)
c. Myristic acid
d. Linolenic acid
e. More than one of the above
44. A phospholipid with the phosphate ester group bonded to choline would be classified as a
a. glucocerebroside
b. cephalin
c. lecithin
d. sphingolipid
e. More than one of the above.
.
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45. Electrophoresis is a laboratory method
a. used to determine enzyme activity
b. that allows for the identification of amino acids and proteins.
c. that is based on the differential migration of charged species within an electrical field.
d. which is used to help diagnose diseases such as sickle cell anemia, lupus erythrematosus,
and some forms of myeloma.
e. More than one of the above.
46. Which is true of the isoelectric point of amino acids?
a. The isoelectric points of all amino acids are the same.
b. It is the pH at which the amino acid conducts electricity.
c. An amino acid at its isoelectric point will not migrate in an electric field.
d. It is the pH at which the amino acid is un-ionized.
e. More than one of the above.
47. Which amino acid is not chiral?
a. alanine
b. arginine
c. glycine
d. phenylalanine
e. None of the above
48. The N terminal amino acid is the peptide ala – gly – leu – his – pro is
a. proline
b. glycine
c. leucine
d. histidine
e. alanine
49. Which of the following is the Fischer projection of L-tryptophan?
a.
b.
c.
d.
COO
NH3
H
CH2
HN
COO
H3N
H
H3N
CH2
COO
H
CH2
H
COO
NH3
CH2
HN
50. Which amino acid is a secondary amine with its nitrogen and the carbon joined as part of a ring
structure?
a. arginine
b. glycine
c. histidine
d. lysine
e. proline
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51. Which pair of amino acids would be found on the internal surface of an membrane protein?
a. leucine and alanine
b. glutamate and serine
c. glycine and asparagine
d. asparagine and lysine
e. histidine and serine
52. Which of the following denaturing agents affects hydrophobic regions in a protein?
a. bases
b. acids
c. heavy metals
d. detergents
e. urea
53. When a protein is hydrolyzed
a. a water molecule is removed from the amide bonds that link amino acids.
b. two amino acids are joined together to form a dipeptide.
c. its primary structure is destroyed, thus destroying the other aspects of its structure.
d. Its primary structure is maintained, but other aspects of its structure are disrupted.
e. More than one of the above.
54. Which pair of amino acids can form a salt bridge?
a. leucine and alanine
b. glutamate and serine
c. serine and tyrosine
d. arginine and glutamate
e. histidine and glycine
55. The type of interaction that is important in maintaining secondary structure of a protein is
a. hydrogen bonding within the backbone
b. hydrogen bonding between the R groups
c. salt bridges
d. hydrophobic interactions
e. More than one of the above.
56. The beta pleated sheet is an example of
a. primary structure
b. secondary structure
c. quaternary structure
d. tertiary structure
e. good housekeeping
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Chem 306
Short Answer
Exam II
Name________________
1. (4 pts) Many drugs undergo chemical modification in the body. Most frequently this process entails a
loss of biological activity and an increase in water solubility which promotes elimination via the
kidneys and urine. Predict the hydrolysis products (acid conditions) of acetaminophen
O
O
OH
H3N
OH
2. (4 pts) The salt magnesium stearate is a filling agent in medical tablets and capsules. It is also the
major component of bathtub rings. Draw the structure of magnesium stearate. Be sure to show the
ionic charges.
O
Mg2+
O
2
3. D-Mannose, which appears in some fruits including cranberry, has been postulated to help prevent
bladder infections by preventing the adhesion of bacteria to the epithelium of the urinary tract and
urinary bladder. Given the following Fischer projection of D-mannose:
a. (8 pts) Draw the cyclic structures (Haworth) of the two anomers of D-mannose and label each
with the correct name.
HO
HO
H
H
CHO
H
H
OH
OH
CH2OH
CH2OH
O
OH
CH2OH
O
OH
OH
OH
OH
OH
beta - D - mannopyranose
______
16
11
OH
OH
alpha - D - mannopyranose
b. (6 pts) Draw a Fischer projection of and name the following.
1. a diastereomer of D-mannose
2. an enantiomer of D - mannose
Drawn structure of allose,
tallose, glucose, idose, gulose,
CHO
OH
OH
or galactose (any non-mirror.
Image)
HO
HO
CH2OH
L - mannose
4. (9 pts) a. Construct the polypeptide tyr – val – cys (pH 4).
amide bonds
O
O
O
HN
CHC
OH
HN
CHC
H3N CHC
CHCH3 CH2
CH2
CH3
SH
OH
b. Circle and label the amide functional groups.
c.
In an electrophoretic analysis at the given pH, will this tripeptide migrate towards a positive or
negative electrode? Explain your answer.
This tripeptide will migrate towards a negative electrode because the tripeptide has an overall positive charge.
d. If the pH of the analysis is increased to 8, how will the electrophoretic migration of the
polypeptide be affected? Explain your answer.
This tripeptide will migrate towards a positive electrode because the tripeptide has an overall negative charge
at this pH. The amine and carboxyl group will be deprotanated (NH2 and COO-)..
4. (4 pts) One of your clients has been prescribed the anti-cancer drug “liposomal doxorubicin (Doxil™,
Caelyx®, Myocet®) “. Explain the term “liposomal” and its role in drug delivery. Include a sketch in your
answer.
The term liposomal indicates that the drug is delivered in a liposome. A liposome is a spherical lipid bilayer
structure that allows for its fusion with cell lipid bilayer. Liposomes are very effective at delivering hydrophilic
chemotherapeutic agents to tumors.
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