CELL TRANSPORT VIDEOS Brownian movement (motion) is the random
movement of suspended particles in a gas or liquid that is
caused by the molecular motion (collisions) of surrounding
molecules (and particles) of the medium. Two primary factors
that influence the rate of movement are temperature and the size
of the suspended particles. The rate of movement increases with
temperature, and smaller particles move faster because they have
less mass (thus, less resistance). The following videos
demonstrate the Brownian motion of particles in milk and in
india ink. Milk contains an assortment of different sized
particles (mostly fat globules), and india ink contains an
assortment of different sized carbon particles. In biological
systems osmosis is defined as the diffusion of water (from an
area of high concentration to an area of low concentration)
across a selectively permeable membrane. The concentrations of
water vary because of the presence/absence of non-diffusible
solute(s). Solutes that are permeable to the me