1. 7 – 3 Cell TRANSPORT
How things get in and out of your cells!

2. Put the following in order:
From smallest unit to largest:
organism
Cell
Organelle
Organ
Tissue
Organ system
How do cells attach together?

3. Cell membrane Made up of a lipid bilayer (2 layers)
The middle is hydrophobic – the outsides are hydrophilic.
Some molecules can pass right through (small, non-polar) but others can only go through in protein channels.

4. Lies outside the membrane, less flexible.
Cell Walls – plants (cellulose), fungi (Chitin), algae and some bacteria (peptidoglycan)
Lies outside the membrane, less flexible.
Allow water, oxygen, CO2 to pass through but offers support for cells.

5. Diffusion –
Movement of any particles from high concentration to low.

6. Osmosis -
The diffusion of WATER through a membrane from high concentration to low.

7. How osmosis works:
Water will enter or leave cell to even out. Know this chart WELL!
Solution Type:
Water Conc:
Solute Conc:
Hypotonic (below)
Higher
Lower
Hypertonic (above)
Isotonic
Equal

8. Tonicity in plant cells
Plants react differently than animals because they have a cell wall that prevents the cell from bursting. They prefer to be in a hypotonic (called TURGID)state – where water will rush in and fill the vacuole for support. We will see this in lab soon!

9. Facilitated diffusion:
Proteins are imbedded in the phospholipid bilayer and act like “gates” that help larger (or charged Na+ ions) molecules pass through. Still diffusion from high to low concentration, but with HELP. For example; glucose – because it is BIG gets in this way!

10. Active transport -
Moving a particle against concentration gradient – requires energy (ATP) to push it out and the help of protein “pumps”.
Ex: Hydrogen ion concentration
&mid=B4DB9EF A11B4DB9EF A11

11. Endocytosis- Into the cell
Phagocytosis is one type:
Pulling material (food, cells)in through folding of the membrane. Human cells, amoeba do this, things with cell walls – not so much, they’re rigid.

12. Exocytosis – Out of cell!
Vacuole from the cytoplasm fuses with cell membrane to expel wastes from cell. Protists use contractile vacuole to get rid of water because they live in freshwater and have no cell wall. C&first=0&FORM=LKVR2