Transcript The Nitrogen Cycle - Whalsay School

The Nitrogen Cycle
My power point presentation is
going to be about the nitrogen
cycle.
The Nitrogen cycle
Plants and animals need a supply of nitrogen to make
proteins. Proteins are essential for growth and other life
processes.
The atmosphere of earth contains huge quantities of nitrogen
gas. However plants can only obtain their nitrogen from the
soil in the form of NITRARES. Animals can get their
nitrogen only by eating plants or other animals.
The nitrogen in the air can be converted into NITRITES in a
variety of ways:
Nitrifying bacteria
There are at least two types of nitrifying bacteria in the
soil:
nitrate bacteria
ammonium
oxygen
nitrate bacteria
nitrites
oxygen
= NITRATES
By this sequence nitrogen in proteins is changed into a
form which can be absorbed by plant roots.
Transformation of plant and
animal protein
Saprotrophic, or putrefying bacteria and fungi decompose
proteins in dead animals and plants. In this process
ammonia is released and immediately dissolves in soil
water. Here, the ammonia combines with soil chemicals to
form various ammonium compounds which converted into
nitrates by nitrifying bacteria.
Picture of Bacteria
Nitrogen-fixing bacteria
Bacteria of this type use carbohydrates and atmospheric
nitrogen to make compounds which are eventually
released in the soil as NITRATES. This process is called
nitrogen-fixation. Some of these bacteria obtain
carbohydrates from the soil humus. Others live inside
the root cells of leguminous plants (e.g. peas, beans,
clover and vetches) where they cause tiny swellings
called root nodules. Here the bacteria obtain both
protection and carbohydrate from the plant cells, and in
return they release nitrates into the plant tissues and the
soil. Leguminous plants are often cultivated in order to
increase the nitrate content of agricultural soils.
Root nodules on a Legume
Lightning
During lightning flashes
extremely high temperatures is
generated. This result in nitrogen
combining with oxygen to form
nitrous and nitric oxide gases.
These gases dissolve in rainwater
and form nitrous and nitric acid.
These acids soak up into the soil
where they react with other
chemicals to form NITRATES.
Picture
The End
This excellent, spectacular, brilliant, magnificent,
outrageous, superhuman, immense piece of work was
brought to you by
BLAINE
MUCHMORE