Homeostasis and Transport

1. Homeostasis and Transport

2. Concentration • The amount of solute in a solution. • Often measured as a percentage. • Deciding factor as to where particles move.

3. Passive Transport • Movement of particles that does not require energy. • Diffusion • Osmosis • Facilitated Transport

4. Diffusion • When particles move from an area of high concentration to an area of low concentration. • Seeks to reach equilibrium • Equilibrium: when the concentration of solute is the same through out the system. • Even when equilibrium is reached, particles will continue to move (even exchange)

5. Diffusion, cont.

6. Osmosis • The diffusion of water through a selectively permeable membrane. • For example, sugar molecules can’t fit through the cell membrane, therefore, the water moves instead.

7. Osmosis • Ex: Same concentrations

8. Osmosis • Ex: salt water plant in freshwater

9. Osmosis • Ex: freshwater plant in saltwater

10. Facilitated Diffusion • Occurs when proteins in the cell membrane move molecules across the membrane. • Helps to “facilitate” or help the movement of sugar molecules. • http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_facilitated_diffusion_works.html