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Decay and the Carbon
Cycle
BY THE END OF THIS LESSON YOU SHOULD BE ABLE TO:


DESCRIBE HOW PLANTS AND ANIMALS RETURN MATERIALS TO THE
ENVIRONMENT



NAME THE TYPE OF ORGANISM WHICH CAUSES LEAVES TO ROT



GIVE A REASON WHY LEAVES DECAY FASTER IN SUMMER
What would happen if nothing ever
decomposed or rotted?
What causes things to decompose or
rot?


Rabbit decomposing pic1.



Rotting  Science@home
Biodegradable v non biodegrable
BIODEGRADABLE


Capable of decomposing



Capable of being broken
down by bacteria and other
microorganisms

Non biodegradable


Cannot be broken down by
biological means
Investigation into factors affecting
decay
What affects the
rate of decay?

TEMPERATURE

High temperatures prevent decay,
low temperatures slow decay

High temperatures destroy
enzymes and proteins, killing
Temperature
the organisms responsible for
decay. Low temperatures
slow the rate of reaction of
enzymes and will prevent
growth and reproduction.
What affects the
rate of decay?

OXYGEN

Lack of oxygen will slow or
prevent most forms of decay

Oxygen is needed for
Temperature
respiration by organisms.
Some bacteria can survive
without oxygen, such as those
used in biogas generators.
What affects the
rate of decay?

WATER

Lack of water will slow or prevent
decay
Temperature

 Water

is needed for
transport and to support
reactions inside
organisms. Decay
organisms need water to
digest their food.
How can we prevent or slow down
decomposistion?


Fridges and Freezers - keeping things cold



Keeping air out is important 



Drying things  germs and mould are just like us, they need water to live.



Smoking, salting and pickling were old ways of preserving as well, these all work by reacting
with the chemicals in fresh food. Pickling uses lots of vinegar, which is an acid. Sugar can
be used to preserve sweet things too by helping to dry them out, sugar sucks in any water
around and stops it getting to the food. You can even put a sugar cube in a container with
your cheese to stop it going mouldy.



Cooking changes the chemicals in food too, which stops them reacting. This is why
canning usually involves cooking, and cooked food lasts better than fresh food.
How is decay useful to plants?


The molecules released during decay are
absorbed by the bacteria, fungi and also back
into the soil from where plants can draw them up
through their roots.



Bacteria in the soil change certain nitrogen
compounds into ammonium compounds that are
necessary for plant growth.



Other decomposers break down dead plants
and animals into simple chemicals. For
example, coal and petroleum are formed from
plants that became buried in swamps and
decayed.



The molecules released by this decay process
include the most important elements carbon and
nitrogen which have their own environmental
cycles.





Decomposition : Twig
How can kitchen and garden waste
be recycled?


There are five necessary conditions or factors
for good decomposition:



Organic material: plant or animal material to
decay



Water: the right amount of moisture



Oxygen: air must be able to get to the
material



Warmth: the temperature cannot be too hot
or too cold



Decomposers: bacteria or fungi are needed
to do the job



You would not get decomposition if one of
these was missing.
Decay and the carbon cycle
Space the final frontier


Gravity - Official Main Trailer [2K HD] - YouTube
If an astronaut were to die in space
would their body decompose?


If you were in a protective space suit
or capsule, it probably would
decompose.



If you were in open space, it would
freeze dry. The extreme cold would
freeze your body and the vacuum
pressure would remove all the
moisture from your body. Your body
would be preserved indefinitely.

More Related Content

Decay and the carbon cycle

  • 1. Decay and the Carbon Cycle BY THE END OF THIS LESSON YOU SHOULD BE ABLE TO: DESCRIBE HOW PLANTS AND ANIMALS RETURN MATERIALS TO THE ENVIRONMENT NAME THE TYPE OF ORGANISM WHICH CAUSES LEAVES TO ROT GIVE A REASON WHY LEAVES DECAY FASTER IN SUMMER
  • 2. What would happen if nothing ever decomposed or rotted?
  • 3. What causes things to decompose or rot? Rabbit decomposing pic1. Rotting Science@home
  • 4. Biodegradable v non biodegrable BIODEGRADABLE Capable of decomposing Capable of being broken down by bacteria and other microorganisms Non biodegradable Cannot be broken down by biological means
  • 5. Investigation into factors affecting decay
  • 6. What affects the rate of decay? TEMPERATURE High temperatures prevent decay, low temperatures slow decay High temperatures destroy enzymes and proteins, killing Temperature the organisms responsible for decay. Low temperatures slow the rate of reaction of enzymes and will prevent growth and reproduction.
  • 7. What affects the rate of decay? OXYGEN Lack of oxygen will slow or prevent most forms of decay Oxygen is needed for Temperature respiration by organisms. Some bacteria can survive without oxygen, such as those used in biogas generators.
  • 8. What affects the rate of decay? WATER Lack of water will slow or prevent decay Temperature Water is needed for transport and to support reactions inside organisms. Decay organisms need water to digest their food.
  • 9. How can we prevent or slow down decomposistion? Fridges and Freezers - keeping things cold Keeping air out is important Drying things germs and mould are just like us, they need water to live. Smoking, salting and pickling were old ways of preserving as well, these all work by reacting with the chemicals in fresh food. Pickling uses lots of vinegar, which is an acid. Sugar can be used to preserve sweet things too by helping to dry them out, sugar sucks in any water around and stops it getting to the food. You can even put a sugar cube in a container with your cheese to stop it going mouldy. Cooking changes the chemicals in food too, which stops them reacting. This is why canning usually involves cooking, and cooked food lasts better than fresh food.
  • 10. How is decay useful to plants? The molecules released during decay are absorbed by the bacteria, fungi and also back into the soil from where plants can draw them up through their roots. Bacteria in the soil change certain nitrogen compounds into ammonium compounds that are necessary for plant growth. Other decomposers break down dead plants and animals into simple chemicals. For example, coal and petroleum are formed from plants that became buried in swamps and decayed. The molecules released by this decay process include the most important elements carbon and nitrogen which have their own environmental cycles. Decomposition : Twig
  • 11. How can kitchen and garden waste be recycled? There are five necessary conditions or factors for good decomposition: Organic material: plant or animal material to decay Water: the right amount of moisture Oxygen: air must be able to get to the material Warmth: the temperature cannot be too hot or too cold Decomposers: bacteria or fungi are needed to do the job You would not get decomposition if one of these was missing.
  • 13. Space the final frontier Gravity - Official Main Trailer [2K HD] - YouTube
  • 14. If an astronaut were to die in space would their body decompose? If you were in a protective space suit or capsule, it probably would decompose. If you were in open space, it would freeze dry. The extreme cold would freeze your body and the vacuum pressure would remove all the moisture from your body. Your body would be preserved indefinitely.