HOMEWORK # 2
BIOL/CHEM 5312
due Friday, February 6, 2015

van Holde et al., Chapter 2, p.104-105.

problems 2.5, 2.6, 2.7, 2.8

For particles, use the Boltzmann constant, k= 1.38 x 10^-16 erg K^-1
For moles, use R= 8.31 J K^-1 mole^-1 (10⁷ erg = 1 Joule)

Also,

1.0. One of the so-called Maxwell relations is

This comes from dE = TdS - PdV ,

since dE is an exact differential,

Therefore, by Euler's criterion,

Using similar expressions for dH and dG, derive two other Maxwell relations.

2.0   ITC problem

Ligand A has an extremely high affinity for a receptor, and it cannot be measured by simple isothermal calorimetry.  A second ligand, B, has an affinity of 2 x 10⁷ M^-1 for the same receptor.  If the affinity for A is measured in the presence of 250 µM ligand B, the apparent value is found to be 2 x 10⁸ M^-1.  What is the affinity of the receptor for ligand A?