Which of the following has the least opportunity for recovery?
a. a forest burned by fire cause by a lightning strike
b. a forest cut down by a logging company
c. a forest flooded for a week following heavy spring rains
d. a forest decimated by an avalanche

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.