Cellular Transport

I.  Diffusion - Describe diffusion:

What direction does it always go?

A. Osmosis- diffusion of water across semi-permeable membranes (lipid bilayer image, phospholipid image)

1.  3 Osmotic Solutions

a.  Hypertonic Solution

b.  Hypotonic Solution

c.  Isotonic Solution

(see blood cells in each solution)
(see normal & hypertonic Elodea cells)
(Quia activity to help differentiate between solutions)

2)  Active transport - movement of molecules across the cell membrane against the concentration gradient with use of cell energy and carrier proteins. (see active transport)

3) Facilitated diffusion - movement of molecules from high to low using carrier proteins.  (see carrier proteins)


II.  Endocytosis - movement of particles from outside the cell to inside (see endocytosis)


III. Exocytosis - reverse endocytosis (movement of particles from inside to outside the cell.) (see exocytosis)