Chapter 15, Question 103

[Chem Student]

Vision depends on the protein rhodospin, which absorbs light in the retina of the eye in a reaction in which one form, metarhodospin I, is converted to another, metarhodospin II. The half-life of this reaction in cattle eyes is 600 micro seconds at 37 C but is 1s at 0 C, whereas in frog eyes the same process has a half-life that differs by a factor of only 6 over the same temperature range. Suggest an explanation and speculate on the survival advantages that this difference prvides the frog?

What is the take away from this question suppose to be? Is it that the lower Ea for the reaction occurring in the frog means that k depends less on T?

[Chem_Mod]

Right, k is depend on T, at lower T the half life is longer meaning that the rate is slower. Think of the arrhenius equation.