(a) Temperature dependence of myosin catalyzed ATP hydrolysis. (a) ln Sβ vs. time at 21°C (▽), 25°C (■), 30°C (○), 37°C (□), 45°C (△), 50°C (●), 60°C (▲). From slopes of straight lines, the apparent rate constants (k) are obtained. (b) The Arrhenius plot of natural logarithms of k vs. 1/T, from which the apparent activation energy is evaluated.