Problem set #3

Due: Monday, September 27

Read ?Barrow: Chapter 2: 2-1-5

?Barrante: Chapter 4

Problems: 1-35, 1-38, 2-1, 2-3, 2-7, 2-12, 2-14, 2-17

1. Take the following expression which describes the probability of finding an electron in the 1s-orbital of the hydrogen atom at a certain distance r from the nucleus and show that the function is at a maximum at when r = a₀.

B. With regard to this weeks Chemistry seminar by Dr. James Weisshaur entitled "Solution Phase Structure of Small Peptides from Liquid Crystal NMR" and the background papers and Web resources (http://gustavus.edu/~eb/chemsem1.html), consider the following question. The molecular conformation of small peptides is important but often even for these small peptides molecular conformation is hard to determine exactly, let alone for large proteins. Along what coordinates might a peptide exhibit flexibility and how much energy might be required to convert between conformers? Draw an example small peptide and give a good estimate for the energies required for conformational change about particular coordinates. List two methods which can be applied to study these conformation.

?Groups will present solutions during class on Thursday. Your group will need to meet before then to solve the problem. Everyone should be involved and will have a chance to present the solutions. Overheads or computer graphics may be a necessary part of your informal presentation (~ 5 minutes). Everyone will be responsible for turning in the solution for all the problems.