Chapter 25.7, Problem 39CC

22-49 Based on your knowledge of the chemical properties of amino acid side chains, suggest a substitution for leucine in the primary structure of a protein that would probably not change the character of the protein very much.

22-45 Proteins are least soluble at their isoelectric points. What would happen to a protein precipitated at its isoelectric point if a few drops of dilute HCl were added?

22-91 Which amino acid does not rotate the plane of polarized light?

22-21 Explain why an amino acid cannot exist in an un-ionized form at any pH.

22-44 How can a protein act as a buffer?