Exam 24: Amino Acids and Proteins

Draw the structure of the following tripeptide (starting with the N-terminal residue and ending with the C-terminal residue),showing stereochemical details on chirality centers only : Val-Trp-Asn

Give the structure of the aldehyde which,upon treatment with HCN and ammonia,followed by heating with aqueous acid,would afford racemic tryptophan.What is this strategy for the synthesis of $\alpha$ -amino acids called?

What is the product of the treatment of a racemic form of dl-phenylalanine with acetic anhydride followed by treatment with deacylase enzyme?

Using the one-letter code names for amino acids,write the structures of all possible peptides containing glycine,threonine and phenylalanine:

Show the steps involved in a synthesis of H-Ala-Val-OH using the Merrifield procedure.

Which of these natural amino acids contains a heterocyclic ring?

The Henderson-Hasselbalch equation shows that the ___ of an acid is the ___ at which the acid is half-neutralized.

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

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

The field that studies all proteins that are expressed at a given time is known as:

The occurrence of this amino acid in a polypeptide chain disrupts an α-helix:

What is the name of the aminoacids F; E; R,respectively:

The folding of the polyamide chain gives rise to higher levels of complexity called the ___ and ___ of the protein.

Draw the structure of the amino acids corresponding to these three-letter codes: a)Trp b)Ile c)Cys d)His

Draw structures to represent what happens when valine is dissolved in a strongly basic solution (pH=14).

Draw the structure of the phenylthiohydantoin product you would obtain by Edman degradation of these peptides.Show the configuration of the chirality center on the heterocycle. a)H-Ile-Leu-Pro-Phe-OH b)H-Asn-Thr-Ser-Gly-Ala-OH

For the accompanying fully-protonated amino acid,what is the arrangement of pK_a values in order of increasing magnitude?

Which amino acid would not have its isoelectric point in the pH range 5-7?

The primary structure of a protein refers to its:

Which of the following would provide a synthesis of leucine?