1. Passive Transport Definition: Type 1 Type 3 Type 2 DIFFUSION OSMOSIS
The process of substances passing through the cell membrane WITHOUT ANY INPUT OF ENERGY BY THE CELL.
Passive Transport
Type 1
Type 3
Type 2
DIFFUSION
OSMOSIS
FACILITATED
DIFFUSION
Definition:
Solute molecules move from an area of high concentra-tion to an area of low conc. Powered by the random motion of molecules.
Key Term:
Equilibrium
Definition:
Cell uses carrier proteins in membrane to allow the diffusion of molecules that can’t pass through membrane alone.
Hypertonic:
Solute conc. Bigr
outside. H2O out
Definition:
Diffusion of water from an area of high H2O conc. (low solute conc.) to low (high solute conc.)
Required for
Ions
(charged
molecules)
Isotonic:
Solute conc. =
Inside & out.
No net H2O
change.
And
Hypotonic:
Solute conc. Lower outside.
H2O in. Hypo-Hippo
Large
Molecules

2. Active Transport
Active transport processes are different from passive ones:
Energy is required.
Substances move UP their concentration gradients from lower conc. to higher.
Equilibrium is PREVENTED.

3. Endocytosis “Endo-” means in. “cyto-” means cell.
“osis” means process of.
What does endocytosis mean?
Endocytosis: the process by which cells take in large amounts of material, by folding in the cell membrane

4. Endocytosis Example
Pinocytosis: non-specific endocytosis of small amounts of extracellular fluid.
Greek: “pino-” = “drinking”

5. Endocytosis Example Phagocytosis:
the endocytosis of solid particles such as bacteria, cell debris, or other solids
Greek: “phago-” = “eating”

6. Phagocytes
Phagocytes, such as some types of white blood cells, engulf foreign cells by phagocytosis.

7. For Protists, Phagocytosis = Eating

8. Exocytosis
Exocytosis is the same process as endocytosis, except in reverse.
The stuff leaving may be:
Proteins released into the ECF
New lipids for expanding the membrane
Membrane proteins
Chemicals for communication, etc. (e.g. dopamine)

9. Exocytosis

11. Endo and Exocytosis – quick review