Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
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
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
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.
12.
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.
