the process by which molecules move from an area of higher concentration to an area of lower concentration
diffusion of water through a selectively permeable membrane
the process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell
the process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out
The movement of substances across a cell membrane without the use of energy by the cell.
movement of substances across a cell membrane using energy..low to high concentration
certain substances can pass through