Why would drinking sea water be dangerous for humans?

Everything that surrounds a particular organism

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.

If a young male's body is just beginning the process of producing sperm, when is it likely that he would ejaculate mature, viable sperm"