Download H. Draw a dipeptide from two amino acids

Chemistry 1152
Review for Exam III
1. Draw each of the following structures.
A. 2-methylcyclohexanal
B. butylmethylamine
C. the hemiacetal functional group
D. the acetal functional group
E. 2-chloro-4-ethylheptanal
F. dimethylpropylamine
G. 1-amino-2-hexanone
H. The amino acid serine in basic solution
2. Name each of the following using correct systematic names.
CH3
A.
CH3 CH2
O
O
B.
CH3 CH2 C CH3
CH C
H
C.
CH3 CH2
NH2
CH2 CH3 CH3
CH CH2
CH
CH CH
CH3
D.
NH
CH3
CH3
CH3
E.
CH3
CH CH CH2
CH3
CH
CH3
I.
CH2
F.
C
CH3 CH2
C
CH2
N
+
CH3
O
CH3
_
CH3
H
CH3
G.
CH2
O
CH3
C
O
H.
CH3
O
CH2
CH2
CH2
CH CH2
CH2
NH2
O
J.
CH3
H
CH3 CH2
CH3 CH2
CH CH2
CH
CH3
CH
O
C
H
CH3
Chemistry 1152
Review for Exam III
Page 2
3. Complete the following reactions. If no reaction occurs, write "NO REACTION".
O
A.
CH3
CH2
+ CH3 C
NH CH3
OH
O
B.
CH3
C
+ CH3 OH
H
O
C.
C
+ NH3
OH
D.
O
+ KMnO4
Cl
E.
CH3
NH2 +
NaOH
CH3 CH CH3
O
F.
C
+ KMnO4
H
G.
Product of “B” above + CH3CH2OH
H. Draw a dipeptide from two amino acids
of your choice. You may use R’s
if you wish.
Δ
I.
&
O
CH3
CH2
C
+
CH3
CH2
NH2
OH
J.
4. The isoelectric point for alanine (R = CH3-) is 6.00. Write the structure for alanine as it
would appear in a buffer solution with a pH of 9.0.
Chemistry 1152
Review for Exam III
Page 3
5. Write the products for the complete hydrolysis of:
O
OH
C
CH3
CH2
CH2
NH2 CH C N CH
O H
C
N CH C
O
H
OH
O
6. Although they have similar molecular masses, the boiling point of butylamine is much higher
than that of pentane. Explain why. Give me some details here, not just a concept. (i.e. your
answer should be more than one or two words.)
7.
Prepare the amine: butylethylpropylamine.
combination that is appropriate.
Use any alkyl chloride—secondary amine
8. A heptapeptide is completely hydrolyzed and found to contain one each of the amino acids:
Gly, Leu and Tyr and two amino acids each of Ala and Phe. Partial hydrolysis of a sample of
the heptapeptide yields the following tripeptides: Gly·Phe·Leu, Phe·Ala·Gly, and
Leu·Ala·Tyr. Using the three letter abbreviations, construct the entire heptapeptide.
O
9. How does the amino acid,
R
NH2
pH = 1
appear in the following water solutions?
CH C
OH
pH = 7
pH = 13
10. Briefly define each of the following:
a) peptide bond
b) isoelectric point
11.
c) denaturation
I give you two test tubes filled with a clear liquid. I tell you one of these is filled with
butanal and the other with butanone (why no number here?). What would you do
chemically to tell me which tube contains which substance.
12. Both heptylamine and 1-heptanol are insoluble in water. If you were given a mixture of these
two compounds, what would you do to separate them? Distillation (heat) will not work.
13. Give me one example of a reaction where a tertiary amine will not react, and one example
where a tertiary amine will react. Be sure to list conditions, etc.
14. Why must insulin be injected rather than taken in pill form?
15. Cinnemaldehyde (a spice/flavoring agent) is show here. What would you convert it to under
the conditions shown?
O
CH
LiAlH4
CH C
H
Chemistry 1152
Review for Exam III
Page 4
16. A compound, C4H10O, reacts with KMnO4 to yield C4H8O. The C4H8O compound does not
react with Benedict’s solution. The C4H8O compound is reduced by H2 (with a Pt catalyst)
to give the original C4H10O compound. Draw a reasonable structure for the C4H8O
compound and a brief statement as to why you think your answer is reasonable.
17. In general, what are the potential problems associated with a strict vegetarian diet?
18. How many ketone structures can be drawn that are isomeric with the aldehyde pentanal?
19. Aldehydes and ketones have lower boiling points than alcohols of similar mass. Why?
20. Write reactions to create a quaternary ammonium salt starting with ammonia. Make all of the
R- groups different. Name your final product.
21. Ethanal vs. Octanal. Which is more soluble in H2O? Which is more fragrant? Why?
22. What structural levels of a protein are affected by hydrolysis? By denaturation?
23. Alcohol (ethanol) can be used as an antiseptic agent, for example before an injection is
given. Why do you think 70% alcohol is used rather than 100% alcohol for this purpose?
24. The compound 4-hydroxybutanal (hydroxyl- means an alcohol group) can form an
intramolecular cyclic hemiacetal. Draw the structure of this cyclic hemiacetal.
25. As a preview of our carbohydrate chapter: spell polysaccharide. _____________________