Download Carbon and Nitrogen Cycles

Carbon and Nitrogen Cycles
Matter is neither created nor
destroyed…. Therefore it has to
cycle around the Earth.
Carbon is always on the move
Carbon is an element.
It is part of oceans, air, rocks, soil and all
living things.
Carbon doesn’t stay in one place. It is
always on the move!
1
Storage reservoirs of Carbon
Atmosphere: Carbon is stored as
Carbon Dioxide
Living things: All living things on
Earth are made up of Carbon.
Fossils: Carbon can be
transformed into fossil fuels if
buried for long periods of time
Rocks: Carbon is a major
component of rocks. Limestone for
example is made of Calcium
Carbonate.
Oceans: Carbon can freely move
in between the oceans and
atmosphere. It is used to make
shells, coral and other components
of the ocean.
Processes of the Carbon Cycle
Photosynthesis: The process of plants taking
carbon dioxide (CO2) out of the atmosphere
and converting it into oxygen (O2)
6CO2 + 6H2O 1C6H12O6 + 6O2
C6H12O6 is a sugar called glucose
Within the plant a process called
cellular respiration converts glucose
into ATP (energy)
ATP stands for Adenosine Triphosphate.
Large amounts of energy are stored in the
chemical bonds. When they are broken they
release energy that can be used!
2
Processes of the Carbon Cycle
Respiration: The process of
releasing Carbon Dioxide back
to the atmosphere.
1C6H12O6 + 6O2 → 6CO2 +
6H2O + ATP
Respiration occurs in both
plants and animals.
When we breathe we inhale
oxygen and exhale carbon
dioxide!
Processes of the Carbon Cycle
Consumption: When animals
eat plants carbon passes from
plants to animals. The only way
animals get carbon is through
eating it.
Decay/Decomposition: When
animals die. Decay releases
carbon. Animal remains can
also be transformed into fossil
fuels if they are buried long
enough.
Refining: Crude fossil fuels are
refined into useable forms of
fuel such as gasoline.
Combustion: When fossil fuels
are burned they release Carbon
Dioxide back to the
atmosphere.
3
Processes of the Carbon Cycle
Exchange with Oceans:
carbon dioxide can freely
move between the
atmosphere and the ocean.
The Oceans are one of the
largest sinks (reservoirs) for
carbon.
Release from forest fires:
When trees in the forest are
burned carbon is released
into the atmosphere
What do you think?
Carbon naturally cycles around the
earth. Usually it is in balance. However,
there are some processes that human
can influence and enhance, such as
combustion and forest fires.
What does this upset of this balance mean
for the earth?
4
The Carbon Cycle Game
http://www.windows.ucar.edu/earth/climate/carbon_cycle.html
The Nitrogen Cycle
Nitrogen is an element. A member of the
nitrogen family.
It is found in living things like plants and
animals.
It is also an important part of non-living things
like the air above and the dirt below.
Atoms of nitrogen don't just stay in one place.
They move slowly between living things, dead
things, the air, soil and water.
These movements are called the nitrogen
cycle.
5
Nitrogen Cycle Reservoirs
Atmosphere: Approximately 80% of the
molecules in Earth's atmosphere are made of
two nitrogen atoms bonded together (N2).
Living Things: All plants and animals need
nitrogen to make amino acids, proteins and
DNA, but the nitrogen in the atmosphere is not
in a form that they can use.
Genetic Material: Nitrogen (N) is an essential
component of DNA, RNA, and proteins, the
building blocks of life.
Processes of the Nitrogen Cycle
Nitrogen Fixation:
By bacteria: Plants and animals
cannot take nitrogen directly out of
the atmosphere. Therefore, it must be
fixed, or taken out of the atmosphere,
by bacteria. These bacteria live in
symbiosis with legumes, a simple nut
like dried fruit within the soil.
By lightning, forest fires and hot lava
flows: These events fixate small
amount of nitrogen. The energy is
enough to break the bonds that hold
two nitrogen atoms together and free
up nitrogen for other chemical
processes.
6
Processes of the Nitrogen Cycle
Nitrogen Uptake: Nitrogen is usually
quickly incorporated into protein and
other organic nitrogen compounds,
either by a host plant, the bacteria
itself, or another soil organism. When
organisms nearer the top of the food
chain (like us!) eat, we are using
nitrogen that has been fixed initially
by nitrogen fixing bacteria.
Denitrification: The loss or removal
of nitrogen or nitrogen compounds;
specifically: reduction of nitrates or
nitrites commonly by bacteria (as in
soil) that usually results in the
escape of nitrogen into the air.
Processes of the Nitrogen Cycle
Decay: When organisms die, their
bodies decompose bringing the nitrogen
into soil on land or into ocean water.
Bacteria alter the nitrogen into a form
that plants are able to use. Other types
of bacteria are able to change nitrogen
dissolved in waterways into a form that
allows it to return to the atmosphere.
7
How do humans affect the nitrogen
cycle?
Certain actions of humans are
causing changes to the nitrogen
cycle and the amount of nitrogen
that is stored in the land, water,
air, and organisms.
The use of nitrogen-rich
fertilizers can add too much
nitrogen in nearby waterways as
the fertilizer washes into streams
and ponds.
The waste associated with
livestock farming also adds large
amounts of nitrogen into soil and
water. The increased nitrate levels
cause plants to grow rapidly until
they use up the supply and die.
The Nitrogen Cycle
8