Imagine you are an astronomer who recently discovered a new planet orbiting a distant star. Which set of characteristics would you use to classify this planet as an inner or terrestrial planet? Check all that apply.
D dense and solid
O very large
O thick atmosphere containing hydrogen and helium
O lacking a solid surface
D located near a star

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.