Diffusion
What is diffusion?
Starter: Round the
room Qs.
What is diffusion?
Competition time
Will you get an easy or a hard one?10 seconds to answer:
1
2
Name 5 specialised What is the job of
cells.
a sperm cell?
4
5
3
What do we use to
look at cells?
6
Name a feature of a Name a feature of a
nerve cell that
root hair cell that
What is the job of
helps it do its job.
helps it do its job.
the root hair cell?
7
If I have 2 lenses of
x40 and x50, what
is the overall
magnification?
8
Name 2 specialised
plant cells
9
Where is Mrs C
going on holiday
this year ?
What is diffusion?
Batting order.
Lesson timeline:
1) Complete starter.
2) Observing diffusion.
3) discussion on diffusion.
4) watching demos on diffusion
• check point – be able to explain that diffusion is from high to low
concentration
Success Criteria
• To define the term ‘diffusion’.
• To be able to explain that diffusion is faster if there is a bigger
concentration difference.
• Give examples of substances that diffuse into and out of cells.
What is diffusion?
Call my Bluff
• Semi Permeable Membrane
What is diffusion?
Call my Bluff
• Semi Permeable Membrane – a membrane,
for example around a cell, that will let small
enough substances through.
• Semi permeable membrane – A membrane
where half of the material is missing.
• Semi permeable membrane – a layer which
completely blocks all molecules from moving
What is diffusion?
through it.
Today’s question…
Why can’t you
smell a fart
straight
away?
What is diffusion?
Think Pair Share.
When will diffusion stop?
Semi permeable
membrane
What is diffusion?
Lets investigate –
1) Potassium
Permanganate.
1 or 2 crystals dropped
into a large beaker of
water. Observe what
happens to the colour of
the water.
2) The spreading of
ammonia gas and
hydrogen chloride gas.
USE A FUME CUPBOARD.
What is diffusion?
Diffusion
Challenge:
• On your white boards write a definition of
diffusion.
• This is the net movement of particles from a
high concentration to a low concentration.
Success Criteria
To define the term ‘diffusion’.
What is diffusion?
Think Pair Share
In which situation will diffusion happen
quickest?
Explain why in your books
What is diffusion?
What is the net movement?
• Competition time
• Work out the net movement in these challenges.
• You can only have 1 challenge at a time. Take it back to your
table and work it out.
• Write your answer down.
• Show me
• I will give you the next.
• First to finish = ???? points
What is diffusion?
1) 30 water molecules move into a cell and 68 move out. What
is the net movement and in which direction is it?
2) 196 amino acids move out of a cell and 456 move in. what is
the net movement and in which direction?
3) 1857 salt molecules dissolved in blood, move into a cell
which has equal salt and water. With this, 2067 water
molecules move. Only 34 salt molecules leave the cell and
1097 water molecules leave the cell. What is the net
movement of water and salt. Will the cell have more salt or
water.?
What is diffusion?
Check point
• If 30 water molecules move into a cell, and 25
move out, what is the net movement into the
cell?
1) 5
2) 25
3) 55
What is diffusion?
What is a Concentration Gradient?
• Hills and graphs have gradients
• Think pair share.
Which is the steepest gradient ?
Which could you move down quickest?
What is diffusion?
moving down a concentration
gradient
Which way will the particles move?
What is diffusion?
Modelling diffusion
• Drain pipes and marbles.
• How good is this model?
What is diffusion?
How does diffusion work in the
body
Identify which molecules in your body need to
move around AND are small enough to move
through cell membranes.
Use the information to help you.
CARD SORT
What is diffusion?
Conclusion Qs
CHALLENGE
Can do
Draw a diagram to Draw a diagram to
show diffusion.
show what
Give examples of
happens during
things that diffuse
diffusion.
in
the
body
and
Describe the model
explain why they
we used and how it
diffuse.
was like real life.
5 points
3 points
C/B
D/C
IRON MAN
Think of a model of
diffusion that could
be used to explain
to students about to
learn about
diffusion.
Write notes about it
so that a teacher
could use it in their
lesson.
8 points
B/A
What is diffusion?
Plenary
• Round the room 1 more time.
What is diffusion?