Exam 24: Amino Acids and Proteins

Which of the following amino acids is theoretically capable of existing in diastereomeric forms?

Which amino acid would have its isoelectric point near pH 10?

C-terminal amino acids can be identified through the use of _____________.

The secondary structure of proteins has three basic types of folding patterns.These are:

Suggest a reasonable strategy for the synthesis of the dipeptide Leu-Phe,using established protocol for peptide synthesis.

Which of these natural amino acids contains an -OH group?

Disulfide bonds in proteins:

Draw the structure of the following tripeptide (starting with the N-terminal residue and ending with the C-terminal residue),showing stereochemical details: Gly-Phe-Met

Which of these natural amino acids contains two carboxylic acid groups?

Which of these natural amino acids,when present in a polypeptide,is likely to exhibit significant hydrogen bonding through its side chain?

Draw the structure of L-phenylalanine and L-valine in Fischer projection.

A pentapeptide has the molecular formula: Asp,Glu,His,Phe,Val.Partial hydrolysis of the pentapeptide gives: Val·Asp,Glu·His,Phe·Val,and Asp·Glu.What is the amino acid sequence of the pentapeptide?

What is the final product formed via the following reaction sequence? Give structural details of all significant intermediates.

A reagent that reacts with most amino acids to give an intense purple color is called ___________.

The purple color of the anion formed in the ninhydrin test for α-amino acids is due to:

Draw the structures of the predominant forms of glycine at pH = 2.0,6.0,and 10.Indicate the direction of migration (toward anode or cathode)for each structure.

Which is an isolable intermediate in the Strecker synthesis of an amino acid?

Which of these amino acids is a D amino acid?

Which attractive force is responsible for maintaining the tertiary structure of a protein?

Which of these natural amino acids contains a phenolic group?