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Energy release
When something burns, heat and light energy is released.
This process will produce energy if
there are 2 main ingredients.
combustion
FUEL + OXYGEN
Carbon
dioxide
+ Water +
If these two and heat are all present then the fuel and
oxygen will react. This reaction is called COMBUSTION.
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What is respiration?
RESPIRATION is the process which releases energy from food.
This is NOT the same as breathing.
We can now write out the full equation for RESPIRATION.
FOOD
(GLUCOSE)
from
digestive
system
+
OXYGEN
from
breathing
system
CARBON
DIOXIDE
waste
product
exhaled
+
WATER
waste
product
exhaled
+ ENERGY
USEFUL!
Combustion is different because it is NOT a controlled
reaction. Respiration IS a controlled reaction which
SLOWLY releases energy from food in the CELLS.
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What type of fuel is required by the body?
The body changes food into a form which can be
carried around the body. This substance is called
GLUCOSE.
Glucose contains energy.
When glucose
reacts with oxygen a
LOT of energy is
produced. Some of
this energy is
released as heat
while the rest is
used by the cells.
The cells do NOT catch
fire.
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How does oxygen get into our body?
The body separates the process of breathing in
and breathing out.
Breathing in is one process and is known as
inhalation . When we inhale we breathe in air,
taking oxygen with it into our lungs.
Breathing out is a separate process and is
known as exhalation . When we exhale we
breathe out the contents of our lungs, pushing
out waste gases like carbon dioxide
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Inhalation
(When we breathe in we inhale)
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Exhalation
(When we breathe out we exhale)
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The Alveoli
Oxygen makes its way into thousands of special air
sacs collectively called the ALVEOLI.
The outside of the alveoli is covered with tiny
blood vessels.
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Not enough oxygen
When anaerobic respiration takes place, the lactic acid
soaks the muscle cells and prevents the muscle cell from
doing its job. This causes fatigue and/or cramp.
After the activity has been
completed people pant and
breathe heavily. This
happens because oxygen is
required to get rid of the
build up of lactic acid.
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Comparing inhaled and exhaled air
What are the big differences between inhaled and exhaled air?
How could you test for these?
Inhaled Air
Exhaled Air
Nitrogen (78%)
Oxygen (20.71%)
Carbon Dioxide (0.1%)
Other
Nitrogen (75.5%)
Oxygen (14.6%)
Carbon Dioxide (4%)
Other
There is another difference……
…… water vapour.
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