1) A zwitterion is a molecule that has both positive and negative charges, resulting in a neutral molecule
2) PI is the isoelectric point of a solution when it is neutral.
3) At any point on a weak acid, singly-protonated (HA) titration curve there exist two species: a weak acid (HA) and its conjugate base (A-). The relative amounts of these species can be determined using the Henderson-Hasselbalch equation.
4) We did this in discussion.
5) 80 mls.
1) We did this in discussion.
2) The sulfhydryl group on cys is polarizable but the one on met is not.
3) The first residue is not a protein amino acid because a sidechain of CH2 does not occur in the 20 protein amino acids. The second residue is serine, but it is in the D configuration, rather than L, which is the configuration for all protein aa's. The third residue is aspartate, but it is linked via the alpha carbon, instead of the alpha carbon. The fourth residue is the would be glycine if I hadn't forgotten the COOH terminal group (sorry!).
4) Come on, you can do this one
Back to Handouts or goto 
153A VOH page