Download Into and Out of the Cell

INTO & OUT OF THE CELL!!!
Cells need to get nutrients and gases in
through the cell membrane.
Wastes must be able to leave the cell.
The
cell membrane is “picky” about what
.
enters and leaves the cell. The membrane is
selectively permeable.
Cells live with liquids all around—
water/salts/gases are dissolved in this liquid.
Concentration is a measure of how much of 1
substance is dissolved in a certain amount of
another substance.
Cells like to keep things equal!! This is called
EQUILIBRIUM
When things are unequal—things move to make it
equal again!!
This is known as DIFFUSION
Molecules moves from areas of high
concentration ( crowded ) to areas of lower
concentration ( spread out )
For example-More
molecules
outside
the cell!
Molecules
equal
out!!
If the substance moving is WATER—special
kind of diffusion known as-- OSMOSIS
Diffusion & Osmosis—require no ENERGY
just happens to equal things out!!
Some molecules are to big to diffuse in/out—
they must use energy—this movement is called
ACTIVE TRANSPORT