What does the large olfactory lobe of a frogs brain suggest?

Olfactory lobe gives the sense of smell. The large size of the olfactory lobe of a frog brain suggests that the maximum part of processing in the brain of frogs is associated with odors that act like an essential homing tool in finding their breeding ground as well as for detecting predators and food. Many tadpoles with the help of chemical scents perform this function of detecting food and predators.

Thus, large olfactory lobe of a frog brain provides great significance to them.  

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?