Amino Acids, Peptides
and Proteins
Chapter 23
Amino Acids, Peptides and Proteins
1. Answer the following:
a. Which amino acid(s) is achiral?
b. Are naturally occurring amino acids D or L?
c. Which amino acids(s) have 2 chiral centers?
Amino Acids, Peptides and Proteins
2. Explain kinetic resolution.
Amino Acids, Peptides and Proteins
3. Draw the following amino acids at pH = 0, 5, and 13.
a. Valine
b. Glutamate
c. Lysine
Amino Acids, Peptides and Proteins
4. Calculate the pI of the following amino acids.
a. Phenylalanine
b. Histidine
c. Aspartic Acid
Amino Acids, Peptides and Proteins
5. What is the net charge of the following amino acids
at the designated pHs?
a. Serine at pH = 4
b. Arginine at pH = 5
c. Glutamic acid at pH = 5
Amino Acids, Peptides and Proteins
6. Which amino acids are the most polar and nonpolar?
Amino Acids, Peptides and Proteins
7. Thin layer chromatography of a solution of
threonine, valine, lysine, alanine and serine yielded
the following; determine which amino acid goes with
each spot?
Amino Acids, Peptides and Proteins
8. Gel electrophoresis of a solution of histidine,
tyrosine, lysine, aspartate and glutamic acid yielded
the following determine which amino acid goes with
each spot?
cathode
anode
Amino Acids, Peptides and Proteins
9. Show how alanine can be synthesized via…
a. HVZ
b. Reductive amination
c. N-Phthalimidomalonic ester synthesis
d. Strecker Sythesis
Amino Acids, Peptides and Proteins
10. Draw the met-ile-tyr-asn-his at pH = 7
Amino Acids, Peptides and Proteins
11. Show how the following peptide can be synthesized
ala-gly-ser
Amino Acids, Peptides and Proteins
12. Distinguish between primary, secondary, tertiary
and quaternary structures of peptides and proteins.
Amino Acids, Peptides and Proteins
13. Descibe denaturation and give examples of possible
causes for denaturation.
Amino Acids, Peptides and Proteins
14. Show the cleavage sites on the following peptide if
introduced to each of the following reagents:
ala-gly-phe-met-ser-lys-tyr-asn-glu-arg-pro-met-leu-his
A. Carboxypeptidase A
B. Edmans
C. Cyanogen bromide
D. Trypsin
E. Chymotrypsin
Amino Acids, Peptides and Proteins
Amino Acids, Peptides and Proteins
Amino Acids, Peptides and Proteins
Amino Acids, Peptides and Proteins
Amino Acids, Peptides and Proteins
Amino Acids, Peptides and Proteins