This document discusses passive and active transport across the cell membrane. It defines the cell membrane as semipermeable, allowing some substances to pass through. Passive transport uses diffusion and osmosis to move substances down their concentration gradient without energy use, while active transport moves substances against their gradient by using transport proteins and cellular energy. Active transport mechanisms include endocytosis, which transports substances into the cell, and exocytosis, which transports them out.

2. Passive and Active
TransportThe Cell
Membrane is
semipermeable
Semi: partly or Somewhat.
Permeable: Substances can
get through.
Some substances can
get through the Cell
Membrane because it
is semipermeable.

3. Passive Transport
 Passive Transport: Transport of
substances into or out of the cell without
the use of energy.

4. Passive Transport
 Diffusion: When a substance moves
from an area of high concentration to an
area of low concentration.
High Concentration Low Concentration Diffusion

5. Passive Transport
 Equilibrium: Occurs when the high
concentrated substance is equally
distributed into the low concentration
substance. Equilibrium
What will happen
when equilibrium
occurs with the
Mio and the
water?

6. Passive Transport
 Osmosis: the diffusion of water through the
cell membrane.
 Water goes from where there is a lot of water to
where there is a little bit of water.
If there is a lot of water outside of the cell and
very little inside, then the water goes from
where to where?
If there is a little water outside of the cell and
a lot inside, then the water goes from where
to where?

7. Passive Transport
Facilitated Diffusion: when a substance is
brought into the cell by transport proteins
in the cell membrane.

8. Active Transport
 Active Transport: when the cell must use
energy to get a substance into or out of
the cell.
Why is this
person using
energy to get
more clothes into
the suitcase?

9. Active Transport
 Cells must use energy when moving
substances against the concentration
gradient, or from an area of low
concentration to an area of high
concentration.

10. Active Transport
• Cells use transport proteins for active transport,
much like facilitated diffusion.
What is the difference between active transport
and facilitated diffusion?

11. Active Transport
 Sometimes the cell uses the cell
membrane to get substances into or out
of the cell.

12. Active Transport
 When the cell membrane moves a
substance into the cell, it is called
endocytosis.

13. Active Transport
When the cell membrane is used to
transport substances out of the cell, it is
called exocytosis.

14. Ticket out the Door
 Define these three terms: High
concentration, low concentration, and
diffusion.
 What are the two forms of active
transport that involve the cell
membrane?
 What is one word that describes the cell
membrane?