Carbon dioxide in the atmosphere
Starter
If I am the answer, what is the question?
• Which process puts carbon dioxide into the atmosphere?
• Which process takes carbon dioxide out of the atmosphere?
Respiration
Respiration is a chemical reaction that
happens in all living cells. It is the way
that energy is released from ______, for
our cells to use to keep us functioning.
glucose + oxygen → carbon dioxide + _____ (+ energy)
Respiration ______ carbon dioxide into
the atmosphere
Water
releases
glucose
Respiration: testing for carbon dioxide
Breathe out into the limewater – what do you notice?
Write two sentences in your book:
When I exhaled into the limewater, it …
This shows that there is ______________ in my breath.
Combustion
Fuels (oil, wood, etc) are substances that
react with oxygen to release useful
energy. Most of the energy is released as
heat, but light energy is also released.
hydrocarbon + oxygen → carbon dioxide + water
Combustion releases carbon dioxide into
the atmosphere.
Photosynthesis
Green plants absorb light energy using
chlorophyll in their leaves. They use it to
react carbon dioxide with water to make a
sugar called glucose. The glucose is used in
respiration, or converted into starch and
stored. Oxygen is produced as a byproduct.
Photosynthesis is the only process which
takes carbon dioxide out of the
atmosphere
The carbon cycle
•You each have an A4 sheet of paper on your desk
•Write your name on the top of the piece of paper then put
your pen down
•You will have one minute to memorise as much as you can of
the image on the board
•You will have one minute to note down as much as you can
•Then you pass your drawing to the person sitting next to you
•Write your name on the paper handed to you
•You have 10 seconds to look at what the person has drawn
•One minute looking at the board
•One minute improving the drawing
•Repeat once more
We will mark as a class – merits if any picture
you have contributed to is fully correct!
•Write your name on the paper
•Pens down
•Eyes facing forwards
Draw what you remember
•Pass your paper to the person sitting to your left
•Write your name on the paper
•Pens down
•Eyes facing forwards
Draw what you remember
•Pass your paper to the person sitting to your left
•Write your name on the paper
•Pens down
•Eyes facing forwards
Draw what you remember
Check the diagram handed to you
9 marks for the arrows
GIVE A MARK OUT OF 14
5 marks for the explanations
Where is
most of
the
carbon
on Earth
stored?
• The water represents the _________
• Before we exhaled, the colour of the UI was _____, showing that
distilled water is _______.
• Exhaled air (air we breathe out) contains higher levels of carbon dioxide
than the air we breathe in because the process of ________ takes place
in our cells, in order to release ________
• When the carbon dioxide entered the water, the colour of the UI
changed to ______.
• This shows that water becomes more ______ when it absorbs CO2
Plenary: the carbon cycle
Match up the boxes to form four full sentences in your book
Carbon dioxide levels in the
Earth’s atmosphere…
Plants and oceans are known
as…
When we burn fossil fuels…
As carbon dioxide levels
rise…
… carbon locked up long ago
is released as carbon
dioxide
… were kept steady by the
natural recycling of carbon
dioxide in the environment
… the reactions of carbon
dioxide in sea water
increase
… carbon dioxide sinks