Molecular Motion
Random and erratic; reflects the kinetic energy of molecules
Velocity
Is lower in larger molecules and increases with higher temperatures
Passive Transport
Transportation and movement through the plasma membrane that is driven by concentration or pressure differences; includes diffusion, filtration, and osmosis
Active Transport
A form of facilitated diffusion that requires energy and carrier proteins that combine specifically with the transported substance; includes phagocytosis, pinocytosis, and receptor-mediated endocytosis
Diffusion
The spreading of particles in a gas or solution from high to low concentrations
Osmosis
The movement of water from low to high solute concentrations
Simple Diffusion
The unassisted diffusion of solutes through a selectively permeable membrane