Problem Set 4 Solution

# Problem Set 4 Solution - Answers to Problem Set#4 1 A The...

• Notes
• 3

This preview shows page 1 - 2 out of 3 pages.

Answers to Problem Set #4 : 1. A. The plot is figure 1 from an excellent review on the stability of thermophilic proteins ( Protein Science , 15 , 1569-1578 ’06). Plugging T = T m into the given equation yields ! G(T) = 0. But ! G(T) = -RT ln(K), so when ! G = 0, K = 1. To show the T S and T H relations, just start from ! G(T) = - RT ln (K) = ! H T ! S . The maximum protein stability will be at the T where ! G is at a maximum. To find this temperature, note the derivative of ! G with respect to T is just ! S. So ! G will be maximized when ! S is 0, which is the definition of T S . Similarly, after some simple algebra and calculus, we find the derivative of K with respect to T is ( ! H/RT) exp(- ! H/RT + ! S/R), which will be equal to 0 when ! H is 0. Thus, K is maximal when ! H is 0, or at T H . B. Just from the shape of the plot, we can see that the curve bends downward, so linear extrapolation of DG based on the slope of the curve in the near-linear region around T M will overestimate the protein stability at room temperature. The linear extrapolation would be exactly correct if ! C P were equal to 0.

Subscribe to view the full document.

• Fall '11
• PONDER
• Proteins, AiB, folding rate, maximum protein stability

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern