Lesson 5: Amino Acids and Acid/Base Properties

• Amino acids
• Know the general molecular structure of amino acids
• Be able to quickly draw the complete molecular structure showing all bonds for all of the following amino acids:
• AA's with nonpolar side chains [Alanine(Ala,A), Valine(Val,V), Leucine(Leu,L), Isoleucine(Ile,I), Phenylalanine(Phe,F)]
• AA's with polar uncharged side chains [Glycine(Gly,G), Serine(Ser,S), Threonine(Thr,T), Tyrosine(Tyr,Y), Cysteine(Cys,C), Asparagine(Asn,N), Glutamine(Gln,Q)]
• AA's with carboxylic acid side chains [Aspartic Acid(Asp,D), Glutamic Acid(Glu,E)]
• AA's with basic side chains [Lysine(Lys,K), Arginine(Arg,R), Histidine(His,H)]
• Acid-base systems
• Predict reactions of acids with water; predict reaction of bases with water.
• Write and use equilibria expressions for dissociation of weak acids and bases, K_a and K_b; pKa’s
• Know the Henderson-Hasselbalch equation: be able to understand and use.
• Predict predominant (and relative amounts) of acid/base forms (e.g. COOH/COO^-,  –NH₃⁺/-NH₂ ) present at a given pH.
• Acid-base properties of amino acids
• Predict acid-base forms of amino acids present at various pH’s
• Relate pH to amino acid functional group solubility in lipids or water
• Understand what isoelectric points (pI) are and how to determine them from the pK_a's of amino acids