Chemistry 332 - Winter 1997

Chapter 15 - Amino Acids and Proteins

New Skills

Knowledge - Level 1

Know the terminology:

amino acid, essential amino acid, amino acid residue
peptide, polypeptide, protein, enzyme, coenzyme, vitamin
N-terminus, C-terminus, alpha-helix, beta-sheet
zwitterion, isoelectric point, electrophoresis

Note - Table 15.1 will be provided:
includes names, structures, and pKa values for the 20 amino acids


Concepts - Level 2

understand the relationship between the pKa values of amino acids and peptides and the different ionization states they may assume in solutions depending on the pH

understand the classification systems for proteins

based on composition (simple or conjugated)
based on shape and solubility (fibrous (insoluble) or globular (soluble))
based on fucntion (enzymes, structural, etc.)

understand the classification system for protein structural features:

primary: amino acid sequence
secondary: chain conformations (alpha-helix, beta-sheet)
tertiary: 3-d structure of the entire protein
quaternary: interactions of multiple polypeptide chains

recognize the various reactions of amino acids and peptides:

peptide bonding
disulfide bonding
ninhydrin test
Edman degradation
BOC protecting group
cleavage by chymotrypsin and trypsin


Applications - Level 3

identify the expected state of ionization of amino acids or peptides based on a given pH and their pKa values

name and give abbreviations for simple peptides

indicate the steps necessary for peptide sequencing by Edman degradation

indicate the steps necessary for a peptide synthesis


Analytical Skills - Level 4 & higher

identify features that contribute to the various levels of protein structure

determine the amino acid sequence of a polypeptide based on partial hydrolysis and other results