1. Endocytosis/Exocytosis
CELL PROCESSES
Diffusion
Osmosis
Passive transport
Active transport
Endocytosis/Exocytosis

2. DIFFUSION
The net movement of molecules from an area of many to an area of few =
HIGH  LOW
Occurs in liquids & gases
When molecules spread evenly throughout a space, know as equilibrium

3. OSMOSIS Diffusion of H2O through cell membrane
Important to cells since 70+% of cell is water and they are surrounded by water

4. PASSIVE TRANSPORT When particles move across the membrane by diffusion
Uses NO ENERGY!
Only small particles
(ex. water, mineral ions, and sugar molecules)

5. ACTIVE TRANSPORT
When particles REQUIRE ENERGY to move across a membrane
Use of transport proteins
Use when cell needs to override diffusion; moves substances from LOW  HIGH concentration
(ex: root cells taking in minerals, p. 74)

6. Please sit quietly and watch the following clip about diffusion and osmosis:
United Streaming: Diffusion_And_Osmosis (2:03)

7. ENDOCYTOSIS (Endo=enter/into; Cytosis=pertaining to a cell)
Particles too big to pass through cell membrane using passive & active transport
1st: Large particle enclosed in part of cell membrane
2nd: Membrane folds inward to form a “bubble” around particle
3rd: The “bubble” pinches off, creating a vacuole/ vesicle

8. EXOCYTOSIS (Exo=leave; Cytosis=pertaining to a cell)
Opposite process of endocytosis
1st: Wastes in vacuoles or proteins packaged by Golgi Body are moved to membrane
2nd: Package fuses with membrane & contents are released to outside of cell