Download i) Suggest reagents and conditions for each step in the following

1. i) Suggest reagents and conditions for each step in the following synthesis of the
amino acid valine, and identify the intermediate A.
(CH3)2CHCHBrCN
A
O
OH
CH3
C
CH
CH
NH2
CH3
ii) Draw the displayed formulae of the compounds formed when valine reacts with
a. aqueous potassium hydroxide
b. nitric acid solution
2. (i) A polypeptide, made up of 5 residues, was reacted with 2 different enzymes, B
and C, underwent partial hydrolysis to produce the following peptides. Deduce the
order in which the amino acids are bonded together in the original polypeptide,
explaining your reasoning.
Enzyme B
Enzyme C
Leu – Ala
Gly – Leu – Ala
Try – Lys – Gly
Try – Lys
(ii) A polypeptide, made up of 6 residues, was reacted with 2 different enzymes, D
and E, underwent partial hydrolysis to produce the following peptides. Deduce the
order in which the amino acids are bonded together in the original polypeptide,
explaining your reasoning.
Enzyme D
Enzyme E
Arg – Try – His
Lys – Gly – Arg
Lys – Gly
Try
Meth
His – Meth
3. The following structure shows the repeating unit within a protein molecule.
SH
NH2
CH2
CH2
NH CH
CO NH CH CO NH CH CO
CH2
OH
a. What reagents and conditions are needed to break the protein into its
constituent amino acids?
b. Draw an alpha helix structure base on this repeating unit, showing clearly the
interactions involved.
c. State, with the aid of diagrams, the bonds that holds this protein structure
together in its unique confirmation.
d. Describe three processes encountered in cooking and preparation of food
and explain how they bring about the conformational changes.