Amino Acids

Functions of Amino Acids 1. Building blocks of proteins 2. Modified amino acids are neurotransmitters, etc.

Standard amino acids are  -amino carboxylic acids Defined by Structure

Stereochemistry Naturally occurring amino acids are L-amino acids

Polarity functional group acidic, basic or neutral Classification of Amino Acids

Amino Acids are Charged at Physiological pH Zwitterion- + and - regions: net charge 0

Ionic- high mp,  solid at room temp very water soluble tidbit: avg mol wt 110 Amino Acid Properties

name and 3 letter abbreviation of all 20 at phys pH Amino Acid Structures

R group dissociates in same manner Consider: neutral, basic, acidic Acid-base Chemistry

R group dissociates in same manner Consider:pH 1, pH = pK carboxy, pH = pI, pH = pK amino, pH 13 Neutral Amino Acid: all but 5

Lab reactions: ninhydrin and FDNB modified amino acids peptide bond formation Other Amino Acid Chemistry

Peptides Dipeptide Nomenclature

peptide bond cleavage –acid or base –some aa destroyed acid-base chemistry- R groups only –pK data –net charge used physiological activity –almost unlimited examples Peptide Chemistry