How do some chemicals increase the risk of a person getting cancer ? A. By causing cell mutations

B. By causing a decrease in the immune response

C. By causing an increase of toxins in the skin

D. By causing a deficiency of Vitamin D

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.