How is the Sun different from planets? a. the sun produces its own light, but planets only reflect light.
b. the sun is spherical in shape, but planets are not.
c. the sun exerts a gravitational pull on objects around it, but planets do not.
d. the sun is made up of elements not found on any of the planets.

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.