Final Exam Solution

Ph they are ionized to the carboxylate and negatively

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: mations of these two poly-amino acids. A good way to think about this is to 5. For polyglutamic would either stabilize or4, the sidechain carboxyl groups are protonated (neutral), acid below pH destabilize the different structures, and to consider which of these forces would be pH consider the forces that while dependent. pH they are ionized to the carboxylate and negatively charged. Charge repulsion at high between the sidechains will be minimized by the helix converting to a more extended ("random") For the representative polypeptideglutamic acid case, draw two simple forces involved. structures for average separationwith the form of the side groups chain conformation which will increase the the low and high pH case, between sidechains indicated to illustrate the (now intramolecular) and hence reduce the electrostatic repulsion. CO2CO2H CO2H CO2H CO2H pH < 4 CO2- CO2CO2- pH > 4 (7.5 points/drawing) For polylysine, the argument is essentially the same, except that the uncharged form (-NH2 -­‐2.5 p at high pH in the helical form, form prot...
View Full Document

Ask a homework question - tutors are online