Transcript THROUGH THE CELL MEMBRANE!!!

AIM:
How do materials get in
and out of a cell ??
**THROUGH THE CELL
MEMBRANE!!!
What is the function of the cell
membrane?
- it is SELECTIVELY PERMEABLE.
What does PERMEABLE mean?
-the ability to let things pass through.
**The cell membrane only allows certain
substances to enter and leave the cell.
- this helps maintain HOMEOSTASIS.
HOW???
It’s in all in the structure!
What is the structure of the cell
membrane?
cell membrane structure:
- the membrane is made of a double
layer of LIPIDS with PROTEINS in
it.
- some of the proteins form a
passageway or pore from the
outside of the cell to the inside of
the cell.
- Small molecules like H2O, O2, CO2 &
glucose are able to DIFFUSE
through the cell membrane b/w the
lipid molecules.
What is DIFFUSION????
-
process in which materials move from an
area where they are more concentrated to
an area where they are less concentrated.
(move from high conc. to low conc.)
WHY???
DRAW IT !
It’s like going downhill, so…
**DOES NOT REQUIRE ENERGY USE !
**ALSO CALLED PASSIVE TRANSPORT!
(WHY?)
What is OSMOSIS??
- the diffusion of WATER!!!
What is ACTIVE TRANSPORT?
- movement of particles across a cell
membrane from an area of LOW conc.
To an area of HIGH conc.
- requires the use of energy (ATP).
- Like going uphill (opposite of
diffusion).
HOW?
- carrier proteins in membrane form
tubes that transport particles in or
out.
Draw it!
How does it help a cell??
1- to keep wastes out of the cell or to
store large amounts of needed
materials.
2- to get large particles in/out of the
cell.
The cell membrane is said to be
SELECTIVELY PERMEABLE. What
does this mean??
- it means that the cell membrane only
allows certain substances to pass in or
out of the cell.
- It “selects” what can enter and leave
the cell.
a) Phagocytosis – when the cell
engulfs large, undissolved
particles – usually solids (cell
eating).
b) Pinocytosis – when the cell
takes in small, dissolved
particles, usually liquids (cell
drinking).