Movement of Substances into and out of Cells

Diffusion

The movement of molecules from an area of high concentration to an area of low concentration, down a concentration gradient

Osmosis

The movement of water particles from an area of high water potential (dilute solution) to an area of low water potential (concentrated solution) across a selectively permeable membrane

Active transport

The movement of substances from a low to high concentration using energy

Factors that affect the rate of movement of substances into and out of cells

Surface area to volume ratio, distance, temperature, concentration gradient

As the surface area to volume ratio increase the diffusion rate

increases

The rate of movement of substances is increased when the distance is

increased

Diffusion happens faster at _________ as molecules have more _____________

higher temperatures; kinetic energy

The steeper the concentration gradient…

the faster the particles will move