Amino Acids, Peptides and

Proteins

Chapter 23

Amino Acids, Peptides and Proteins1. 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 Proteins2. Explain kinetic resolution.

Amino Acids, Peptides and Proteins3. Draw the following amino acids at pH =

0, 5, and 13.a. Valineb. Glutamatec. Lysine

Amino Acids, Peptides and Proteins4. Calculate the pI of the following amino

acids.a. Phenylalanineb. Histidinec. Aspartic Acid

Amino Acids, Peptides and Proteins5. What is the net charge of the following

amino acids at the designated pHs?a. Serine at pH = 4b. Arginine at pH = 5c. Glutamic acid at pH = 5

Amino Acids, Peptides and Proteins6. Which amino acids are the most polar

and nonpolar?

Amino Acids, Peptides and Proteins7. 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 Proteins8. 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 Proteins9. Show how alanine can be synthesized

via…a. HVZb. Reductive aminationc. N-Phthalimidomalonic ester synthesisd. Strecker Sythesis

Amino Acids, Peptides and Proteins10. Draw the met-ile-tyr-asn-his at pH = 7

Amino Acids, Peptides and Proteins11. Show how the following peptide can be

synthesizedala-gly-ser

Amino Acids, Peptides and Proteins12. Distinguish between primary,

secondary, tertiary and quaternary structures of peptides and proteins.

Amino Acids, Peptides and Proteins13. Descibe denaturation and give

examples of possible causes for denaturation.

Amino Acids, Peptides and Proteins14. 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 AB. EdmansC. Cyanogen bromideD. TrypsinE. 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