1. What realization did Dr. Natterson Horowitz come to due to her work as both a cardiologist at
UCLA and a contractor who helped the Los Angeles Zoo? What question did that raise in her
mind?

Lactase is essential for digesting lactose in milk. this enzyme is specific for this sugar. why? molecules and active sites vary in size; only properly sized molecules can fit.there is a precise compatibility between the active site and the lactose molecule.specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed.reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules.