DiffusionThe spread of particles through random

motions from regions of higher concentrations to regions of lower

concentrations

Simple DiffusionRequires NO energy

Molecules move from areas of HIGH to Low concentration

DiffusionDiffusion is a PASSIVE process which means no energy is used to make the molecule move, they have a natural KINETIC ENERGY

Diffusion of Liquids

When the molecules are even throughout a space - it is called EQUILIBRIUM

Concentration gradient - a difference between concentrations in a space.Molecules will always move down the concentration gradient, toward areas of lesser concentration.

Think of food coloring that spreads out in a glass of water, or air freshener sprayed in a room.

Diffusion through a MembraneSolute moves DOWN concentration gradient (HIGH to LOW)

How Diffusion Workshttp://highered.mcgraw-hill.com/sites/

0072495855/student_view0/chapter2/animation__how_diffusion_works.html

Turn to your partner and discuss different examples

of diffusion in your everyday life.

Some major examples of diffusion in biology: Gas exchange at

the alveoli — oxygen from air to blood, carbon dioxide from blood to air.

Diffusion in Photosynthesis

Gas exchange for photosynthesis — carbon dioxide from air to leaf, oxygen from leaf to air.

Diffusion in Respiration

Gas exchange for respiration — oxygen from blood to tissue cells, carbon dioxide in opposite direction.

Diffusion in Transfer of Transmitter Substance

Transfer of transmitter substance — acetylcholine from presynaptic to postsynaptic membrane at a synapse.

Diffusion of Water- Osmosis

Osmosis — diffusion of water through a semipermeable membrane.

http://www.youtube.com/watch?v=sdiJtDRJQEc

JournalsDefine the following terms in your own

words:-diffusion-equilibrium-osmosis