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Chemistry 104-1
Professor Fleming Crim
Spring, 2004
Name ____________________________
TA ______________________________
Section ___________________________
1.
This test contains six pages and a periodic table.
2.
There are 16 multiple-choice questions. Circle only ONE answer for each question.
3.
You have 50 minutes to work on the exam.
4.
Put your name on each page.
Page 2
1.
How many structural isomers exist for C5H12?
a.
b.
c.
d.
e.
2.
Optical isomers have non-superimposable mirror images.
There are two types of stereoisomers - geometric and optical isomers.
Enantiomers are pairs of non-superimposable molecules.
A cis isomer commonly rearranges into a trans isomer at room temperature.
Molecules with non-superimposable mirror images are chiral.
The C=O linkage occur in molecules with the following functional groups EXCEPT
a.
b.
c.
d.
e.
5.
butane
2-pentyne
propene
2-ethylbutane
3-hexene
All of the following statements regarding isomers are correct EXCEPT
a.
b.
c.
d.
e.
4.
1
2
3
4
8
Which of the following hydrocarbons can have cis and trans isomers?
a.
b.
c.
d.
e.
3.
Name _____________________________
esters
ketones
carboxylic acids
amines
aldehydes
What class of compounds is responsible for many of the distinctive odors of artificial flavors
Page 3
Name _____________________________
and perfumes?
a.
b.
c.
d.
e.
6.
Optical activity is a common aspect of biological molecules. Select the INCORRECT
statement below concerning optical activity.
a.
b.
c.
d.
e.
7.
A red precipitate forms.
A ketone is produced.
Silver ions are produced.
An alcohol is produced.
A carboxylic acid is produced.
Hydrogen bonding is very important to life. Select the statement below that does NOT apply to
hydrogen bonding.
a.
b.
c.
d.
e.
9.
Nature typically produces one enantiomer in preference to the other.
The enantiomers of a compound have the same molecular formula and have similiar, but
not identical, physical properties such as their solubility, melting points, etc.
Optical activity concerns non-superimposable mirror images.
A common way to have optical activity is to have a carbon atom with four different
groups attached.
A plane of polarized light is rotated in different directions by the two enantiomers of a
compound.
When aldehydes react with Tollen’s reagent to produce the silver mirror we saw in class,
a.
b.
c.
d.
e.
8.
esters
alkanes
aldehydes
amides
amines
Hydrogen bonding is the force that is often responsible for many of the structural aspects
of proteins.
Hydrogen bonding allows many very large organic molecules to be soluble in water.
Sugars are an example.
Hydrogen bonding is the force that allows salts like sodium chloride to dissolve in
water.
The lack of hydrogen bonding is what gives large hydrocarbons their characteristic
oil-like behavior.
Hydrogen bonding can occur between a hydrogen atom attached to a small
electronegative atom like oxygen and a similar function on another molecule.
Which group contains only examples of addition polymers?
Page 4
a.
b.
c.
d.
e.
Name _____________________________
polyester, polystyrene, polyisoprene
polamide, polyester, polyvinylchloride
polyamide, polyester
polypropylene, polyamide, polysaccharide
polystyrene, polypropylene, polyvinylchloride
10. A peptide linkage forms when the __________________ group of one amino acid reacts with
the ______________________ group of another amino acid.
a.
b.
c.
d.
e.
alpha carbon; R group
amine group; carboxylic acid
alpha carbon; amine group
R group; carboxylic acid
R group; alpha carbon
11. The secondary structure of a protein is determined by
a.
b.
c.
d.
e.
the identity and order of its amino acids.
hydrogen bonding between C=O groups and H atoms on amine groups, forming alpha
helices or beta-pleated sheets.
the overall shape of the protein resulting from complex turns and folds.
the degree of interaction among separate protein subunits.
interactions such as ionic bonding and sulfide linkages.
12. A series of statements are given concerning monosaccharides. Which statement is incorrect?
a.
b.
c.
d.
e.
Glucose and fructose are two common monosaccharides.
Both are six-carbon compounds.
Both have several optically active centers.
A linear structure is not the only configuration for these materials.
There are two cyclic structures and one linear sturcture. In solution, the linear structure
is more common.
13. Amino acids polymerize in reactions to form a peptide bond between amino acid molecules.
What is a possible dipeptide formed in the reaction of glycine with phenyalanine?
Page 5
a.
b.
c.
d.
e.
Name _____________________________
Figure a
Figure b
Figure c
Figure d
Figure c and Figure d
14. DNA is composed of many repeating units called nucleotides. Which of the following is NOT
part of a nucleotide found in DNA?
a.
b.
c.
d.
e.
a nitrogen base
deoxyribose
an amino acid
a sugar unit
a phosphate unit
15. The amino acids R = -H, -CH3, -CH(CH3)2, -CH2OH, -CH2SH are known as glycine, alanine,
valine, serine and cysteine, respectively. Name the following tripeptide:
Page 6
Name _____________________________
NH2CH(CH3)CONHCH(CH2OH)CONHCH(CH2SH)COOH
a.
b.
c.
d.
e.
gly-ala-ser
ala-ser-cys
gly-ser-cys
ala-val-ser
val-ser-cys
16. Select the incorrect statement about the amino acids in the previous problem.
a.
b.
c.
d.
e.
None have acidic side chains.
None have basic side chains.
All are chiral molecules.
Alanine and valine have hydrophobic side chains.
Serine has a polar side chain.