Exam 24: Amino Acids, Peptides, and Proteins

What is the practical limit on the use of carboxypeptidase in providing sequence information?

Provide the major organic product in the reaction of L-methionine with benzyl chloroformate.

Show how 3-methylthiopropanal may be converted to methionine.

Disulfide linkages can form between ________.

What is the isoelectric point of lysine within in +/- 1 pH unit?

How could you make the tripeptide Ala-Ala-Gly using the Merrifeld Synthesis? Make sure to specify all the protecting groups needed.

Which of the following indicators is commonly used to visualize bands of amino acids?

What is the major end product of the following reaction series?

Addition of alanine to distilled water will produce ________.

Draw the neutral form of L-phenylalanine in a line-wedge structure with the appropriate stereochemistry.

The pI of alanine is 6.0. Draw the structure for the predominant form of leucine that exists in: a. an aqueous solution of pH = 4.0 b. an aqueous solution of pH = 6.0 c. an aqueous solution of pH = 8.0

Most naturally occurring amino acids are L-amino acids. Does this mean they are levorotatory? Explain.

A polypeptide was treated with a certain enzyme to yield the following amino acid sequences. What enzyme was used to induce the observed fragmentations? Val-Pro-Phe Leu-Ser-Lys-Glu-Trp Arg-Ile-Ser-Ser-Leu-Tyr

Provide the structure of L-aspartic acid at pH 12.0.

If the side chain of asparagine is hydrolyzed, what amino acid is formed?

Proteins which provide all the essential amino acids in about the right proportions are called ________.

Which of the standard amino acids is achiral?

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

Draw the form of L-lysine which is present at biological pH, pH = 7.4.

What name is given to a protein infectious agent that is thought to promote misfolding and polymerization of normal protein molecules and that is believed to cause Creutzfeldt-Jakob Disease?