Diffusion
Sunday, 14 March
2021
L.O. To be able to describe diffusion of particles.
Settling Task:
In your opinion, what is the worst
thing you have smelt? Explain your
answer
Today I would like to Achieve …
Core: Recall what is meant by diffusion.
Extension: Describe examples of diffusion in animals and plants
Killer: Experiment how hot temperature affects the rate of
diffusion.
Independent (3 mins)
Self Assess
Starter – Spelling test
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2.
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10.
Diffusion
Concentration
Gradient
Osmosis
Active Transport
Membrane
Temperature
Energy
Mitochondria
Respiration
Self assessment
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2.
3.
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10.
Diffusion
Concentration
Gradient
Osmosis
Active Transport
Membrane
Temperature
Energy
Mitochondria
Respiration
10
Demo
• You will be given a stop-watch and I will have
a can of deodorant.
• You must close you eyes and start the stopwatch once I have sprayed the deodorant
can.
• Stop the stop-watch when you can smell the
substance.
• Compare how long it took for you to smell
the substance to somebody else in the room.
Think Pair Share
Why can you NOT
smell a fart
straight away?
Smelly gases!
When you fart, you give off gases which
spread through the air…
DIFFUSION means that the ‘smelly’
particles spread through a room on
their own
All read round robin
The particles in liquids and gases can move around freely, this movement of
particles from one area to another is called diffusion.
The particles move from a high concentration to a low concentration- this means
they spread out within the liquid or gas.
“The gradual movement of particles where there are lots of them to places where
there are fewer“
An example of this is when a tea bag is put into hot water. The tea particles diffuse
from the tea bag to fill the cup of water.
Diffusion is the m________ of particle from an area
of h_______ concentration to an area of l_______
concentration until they are e______ spread out.
Keywords
Low, High,
movement,
evenly
Diffusion is the movement of particle from an area of
high concentration to an area of low concentration
until they are evenly spread out.
What is diffusion?
Copy the two diagram and label which is BEFORE
diffusion and which is AFTER.
What is diffusion?
Where will the pink dots move
High
concentration
Low
concentration
Pink dots will move INTO the cell
Where will the blue/pink dots move?
Low
concentration
High
concentration
Blue/pink dots move OUT of the cell
Where will the blue dots move?
High
concentration
Low
concentration
Blue dots move INTO the cell
Where will the orange dots move?
Low
concentration
High
concentration
Orange dots move OUT of the cell
Think Pair Share
• What do all living
cells need?
• What do they need
to get rid of?
An animal cell
food
waste
water
oxygen
carbon
dioxide
Why is diffusion useful?
• Cells can use diffusion as
a way of getting
important particles in
and out of them.
• Diffusion is particularly
useful as it does not use
any energy.
• To get into a cell,
particles have to pass
through a partiallypermeable membrane.
• This is only good for
small molecules, though
– like oxygen and carbon
dioxide.
Examples of diffusion in organisms
Stoma in Leaf
Alveoli in Lung
Oxygen into an Animal Cell
oxygen
carbon
dioxide
oxygen
carbon
dioxide
oxygen
PRACTICAL: How does temperature effect the rate (speed) of diffusion?
Question: Will the cross disappear quicker with
hot or cold water?
Equipment
- 2 x 100ml Beaker
- Potassium permanganate crystals pot &
tweezers
- White paper with black cross marked on it
- Hot water
- Cold water
- Stop Watch
Conclusion
Describe which temperature of water made the cross disappear the
quickest
Explain how temperature affects the rate of diffusion.
As the t________ of the liquid/gas i________ the time taken for diffusion to take
place d________. This is because the p________ that are diffusing have more
e________ and therefore, will move f________.
Suggest why swimming in warm oceans may be dangerous if you have a cut
Self assess
Describe which temperature of water made the cross disappear the quickest
The hot water caused the cross to disappear quicker compared to the cold
water.
Explain how (give reasons) temperature affects the rate of diffusion.
As the temperature of the liquid/gas increased the time taken for diffusion to
take place decreased. This is because the particles that are diffusing have more
energy and therefore, will move faster.
Suggest why swimming in warm oceans may be dangerous if you have a cut?
Your blood will diffuse quicker in warm waters so the blood may be sensed by
the sea creatures.
Today I would like to Achieve …
Core: Recall what is meant by diffusion.
Extension: Describe examples of diffusion in animals and plants
Killer: Experiment how hot temperature affects the rate of
diffusion.