Assertion: biological membrane | /r/MadeOf | receptor
Facets:
Source sentences:
text: Biological membranes have three primary functions: (1) they keep toxic substances out of the cell; (2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment; and (3) they separate vital but incompatible metabolic processes conducted within organelles.