Cells, as well as the entire organism, must work to maintain homeostasis in a constantly changing environment. Active transport is the movement of particles against a concentration gradient and requires energy. _____________ and _____________ are forms of active transport that move large particles into and out of cells.
simple diffusion; ionic molecules
endocytosis; exocytosis
osmosis; sodium-potassium pump
Facilitated diffusion; lipophilic molecules
