ACTIVE TRANSPORT
Moving substances
against their
concentration
gradient
Cost energy!!!
Types of Active
Transport
 Sodium-potassium
pumps
 Endocytosis
 Exocytosis
SODIUM POTASSIUM PUMPS
IN ANIMAL CELLS ONLY
Moves 3 sodium ions
out of the cell and
brings in 2
potassium ions.
Why?
 Prevents sodium from
accumulating in the cell
 Maintain concentration of
sodium and potassium
across the cell membrane
STEPS OF SODIUM POTASSIUM PUMP
1.
2.
3.
4.
Three sodium ions
inside the cell bind to
the pump with an ATP.
The pump changes
shape to transport the
sodium ions out.
Two potassium ions
bind to the pump
outside of the cell.
The potassium ions are
transported into the
cell and released.
STOP- WATCH IT HAPPEN!!!
https://www.youtube.com/watch?v=P-imDC1txWw
ENDOCYTOSIS
Movement of
substances into the
cell.
1. Cell membrane
forms a pocket
around the
substance
2. The pocket closes
up and pinches off
of the membrane
to form a vesicle.
EXOCYTOSIS
Movement of
substances out of
the cell
Vesicles fuse with the
cell membrane
and release their
contents
Used by the cell to
export proteins.
STOP- WATCH IT HAPPEN
https://www.youtube.com/watch?v=DuDmvlbpjHQ
COMPARE AND CONTRAST
Compare and contrast active transport
and passive transport.