Download The Carbon Cycle

The Carbon Cycle
Additional Biology
Learning objectives
Key Objective
• Represent the flow of carbon in a cycle
• State the link between photosynthesis and
respiration (C grade)
• Label a simple carbon cycle (B grade)
• Explain why the carbon cycle is so important to
sustaining life (A* grade)
Why is carbon important?
• Carbon is the main constituent of all living
cells (biochemistry, organic chemistry)
• Carbon can form long chained-molecules
which are the basis for fats,
carbohydrates, nucleic acids (DNA and
RNA) and proteins.
• Component of fuel (coal and gas)
• Use in nanotubes for computers
The Carbon Cycle
• Plants take in CO2 because they need carbon
and oxygen to use in photosynthesis
• Through photosynthesis plants make
glucose (carbohydrate) and other substances
e.g. protein
• When animals eat plants they use some of
the carbon containing compounds to grow
• Some carbon-containing compounds are
used to release energy by respiration.
A little video for you….
AQA Science © Nelson
Thornes Ltd 2006 6
The Carbon Cycle
1.
2.
3.
4.
5.
6.
Carbon dioxide is removed from the environment by
……………… in the process of ………………… The carbon
from the carbon dioxide is used to make ……… ,
………………………… and proteins which make up the body
of plants.
Some of the carbon dioxide is returned to the atmosphere
when plants ………………………………
When green plants are eaten by ………………, some of the
carbon then becomes part of the ………… , ………………
and proteins which make up their bodies.
When animals …………………… this carbon is released into
the atmosphere as …………… ………………
When plants and animals die, ………………………feed on
their bodies. Carbon is released into the atmosphere as
………………… ……………… when these organisms
……………
Sometimes, when plants die, they are turned into fossil fuels.
The ……………… is released back into the atmosphere when
these fuels are ……………
The carbon cycle
True or false?
Green plants use carbon
dioxide in photosynthesis.
True
AQA Science © Nelson
Thornes Ltd 2006 9
Combustion removes carbon
from the atmosphere
False – combustion releases carbon
dioxide gas
AQA Science © Nelson
Thornes Ltd 2006 10
The largest store of carbon is
the atmosphere
False – more is found in marine
organisms and limestone rock deposits
AQA Science © Nelson
Thornes Ltd 2006 11
Respiration adds carbon dioxide
to the atmosphere
True
AQA Science © Nelson
Thornes Ltd 2006 12
Respiration only occurs in
animals
False – both animals and plants respire
AQA Science © Nelson
Thornes Ltd 2006 13
Decomposers remove carbon
dioxide from the atmosphere
False – they respire and release carbon
dioxide
Fossil fuels represent a huge
(but decreasing) store of
carbon
True
AQA Science © Nelson
Thornes Ltd 2006 15
Increasing carbon dioxide may
cause global cooling
False – scientists think it will cause global
warming
AQA Science © Nelson
Thornes Ltd 2006 16
Energy is transferred from
plants to animals to
decomposers
True
AQA Science © Nelson
Thornes Ltd 2006 17
Respiration releases energy
to the environment in the form
of heat
True
AQA Science © Nelson
Thornes Ltd 2006 18