Download The Cell in Action


 For the cells that make up your body and the body of
every other living thing to survive they must be
constantly at work. Never a dull moment in a cell.
For everything to run smoothly, some important
processes must be in place. If they don’t work, you
don’t work!!!
How do materials move into & out of cells?
Small particles move into & out of a cell by one of 2
processes: passive transport or active transport.
Movement of Small Particles

 Passive Transport: the
movement of dissolved
materials across the cell
membrane without using the
cell’s energy (ATP) - particles
move from an area high
concentration to an area of low
concentration
 Includes:
 Osmosis
 Diffusion
 Facilitated diffusion

 Osmosis: the diffusion of water across a cell
membrane
 Diffusion : the movement of particles, through the
membrane’s lipid molecules, from an area of high
concentration to an area of low concentration.
 Facilitated Diffusion: the movement of particles,
through protein channels, from an area of high
concentration to an area of low concentration

 Active Transport: particles
move from an area of low
concentration to an area of
high concentration through
proteins embedded in the cell
membrane. This process does
require energy (ATP).
Movement of Large Particles

 Endocytosis: cell membrane surrounds a particle &
encloses it in a vesicle and is brought into the cell

 Exocytosis: vesicle forms at the endoplasmic
reticulum or Golgi complex and carry the particles to
the cell membrane for export from the cell