Transcript Moving Cellular Materials

Moving Cellular
Materials
Pg. 74-79
Passive Transport

A cell’s membrane is semi permeable or
selectively permeable which means it
allows some things to enter or leave the
cell while keeping other things outside or
inside the cell.
You could also say that a strainer is
semi permeable.

Passive Transport

Passive transport is the movement of
substances though a cell membrane
WITHOUT energy. Substances go with
the concentration gradient.
Diffusion
is one type of
passive transport. It is
the movement of
molecules from an area
where there are more of
them to an area where
there are less.
Passive Transport


Diffusion occurs until
equilibrium is reached.
This means molecules
are equal in both
areas.
Osmosis is the diffusion
of WATER through a
cell membrane.
http://www.geocities.c
om/piratord/browni/Dif
us.html
Active Transport


Active transport takes
place when energy is
used to move materials
through a membrane.
Substances go against the
concentration gradient.
This occurs when a substance is needed in
a cell even though the amount inside the
cell is already greater then the amount
outside.
Active Transport

Carrier or transport proteins bind with the
needed particle and go through the cell
membrane.