--
vivuivronty.
- Applying Concepts Black bears are roaming
through a new housing development in search
of food, even though the housing develop-
ment is still surrounded by forest. How can
you account for the bears' behavior?

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.