Exam 24: Amino Acids, Peptides, and Proteins

Which of the following amino acids has a nonpolar side chain?

The reagent used in the determination of the N-terminal amino acid residue of a peptide is ________.

Which of the following reagents are commonly used to acylate the amino group of an amino acid?

Which of the following amino acids has its isoelectric point at the highest pH?

Complete hydrolysis of a hexapeptide gives 2 Gly, Leu, Phe, Pro, and Tyr. Reaction of the peptide with phenylisothiocyanate gave the phenylthiohydantoin of Pro. Partial hydrolysis of the peptide gave the following fragments: Phe-Gly-Tyr, Gly-Phe-Gly, Pro-Leu-Gly, Leu-Gly-Phe. What is the structure of the peptide?

Draw the dipeptide Val-Tyr.

Show where trypsin would cleave the peptide shown below.

How can an α-ketoacid be converted to an α-aminoacid?

________ of a protein usually results in the precipitation of the protein and loss of its biological activity.

Provide a structure of the tripeptide SGD.

Which amino acid's side chain is negatively charged at biological pH, pH = 7.4?

Draw the Fischer projection of L-glutamic acid at a pH of 12.

An amino acid analyzer can be used to determine ________.

Draw the structure of the tetrapeptide Ser-Leu-Phe-Pro.

Which of the following will result in removal of a benzyl ester protecting group?

Provide the necessary reagents to convert propionic acid to alanine.

Provide the structure of L-arginine at pH 2.0.

When a disulfide linkage is formed, the compound containing this new linkage has been ________.

Provide the single letter code for the following peptide Arg-Phe-Tyr-Cys-Asp-Trp-Gln-Ala-Glu-Glu-His-Lys

When drawing a peptide, the C-terminus ________.