Determining the reactive intermediates in metalloenzymes is a very involved task, and requires drawing from many different spectroscopies and physical methods.  The facile activation and oxidation of methane to produce methanol is one of the "holy grails" of inorganic chemistry.  Strategies exist within materials science and organometallic chemistry to activate methane, but using the enzyme methane monooxygenase, nature is able to carry out this difficult reaction at ambient temperatures and pressures (and in water, too!).

This is an in class exercise that I use to emphasize the need for metal ion transport and storage in biochemistry.  Applying the Van't Hoff equation to the Ksp value at 25°C for ferric hydroxide, students calculate the iron concentration at which ferric hydroxide would begin to precipitate out in the blood.  It' s an interesting problem that requires very little math beyond that used in gen chem, and the answer is in stark contrast to the amount of iron that we actually store in our bodies.  

I was taught (many years ago) the common misconception that fitting the linearized form of the Eyring equation overstates the error in the intercept because on a 1/T axis, the intercept is at infinite temperature, and the intercept is far from the real data. While researching various methods of data fitting, I stumbled across this great article from the New Journal of Chemistry (New J.