1. *This is another function of the cell membrane—what a job!
Cellular Transport
*This is another function of
the cell membrane—what a
job!

2. Cellular transport is the study of how particles move into and out of the cell
Remember: in order to maintain
homeostasis (a steady state) within the cell, the cell must constantly move things into and out of itself. The cell membrane is structured in such a way to help with this process.

3. Picture 1:
Let’s draw a cell membrane!

4. B. We call this model of the cell
membrane the fluid mosaic model The cell membrane is not still—it is always moving (as we saw on the
computer). The cell membrane can
look slightly different at any time (mosaic).

5. Two main types of cellular transport
A. Passive Transport
B. Active Transport

6. III. Passive Transport
Passive transport is the movement of particles across the cell membrane (in or out of the cell) with the concentration ([ ]) gradient.
1. With the concentration gradient means
from high to low concentration.

7. Passive Transport
Picture 2a: Passive (high to low)
Cell membrane

8. 2. This means that the particles move
from an area where there is a lot of
something to an area where there
is a 1 to 1 ratio of that same thing
until there are equal or correct
amounts on both sides of the
membrane.

9. 3. Passive transport does not require
3. Passive transport does not require energy in the form of ATP in order to occur.

10. B. Types of Passive Transport
1. Simple Diffusion: the movement of
small particles straight across the
phospholipid bilayer.
Ex. O2 & CO2

11. 2. Osmosis: the movement of water
molecules straight across the
phospholipid bilayer.

12. 3. Facilitated Diffusion: the movement of
larger particles across the cell
membrane with the help of transport
proteins. (hot dogs)
a. Each transport protein imbedded
in the cell membrane is specific to
a certain type of molecule that it will let
into or out of the cell.

14. IV. Active Transport A. Active transport is the movement of
particles across the cell membrane
(into or out of the cell) against the
concentration ([ ]) gradient.
1. Against the concentration
gradient means from low to high concentration.

15. Active Transport
Picture 2b: Active (low to high)
Cell Membrane

16. 2. This means that the particles
move from an area of where
there is a 1 to 1 ratio of
something to where there is a lot
of that same thing until there are
the correct amounts on both
sides of the membrane.

17. 3. Active transport does require
energy in the form of ATP in
order to occur—in fact, 30-40%
of all the energy that your body
uses is used for cellular transport.

18. B. Types of Active Transport
1. Transporter Protein Mediated (helped):
this type of AT uses special transport
proteins to move particles against the
concentration gradient. (Pac man)
a. When you use your model to
demonstrate this, you have to
physically move the transporter
protein (think: this requires energy)

19. 2. Endocytosis and Exocytosis:. these types of transport are
2. Endocytosis and Exocytosis: these types of transport are called Bulk Transport
Endocytosis:
(into the cell)
Exocytosis:
(out of the cell)