Carbon and Nitrogen Cycle

2. BIO = “life”
GEO = “earth”
CHEMICAL = “elements”
- Cycling of Substances
- Substance Turnover
- Is a pathway by which a chemical element or
molecule moves through both biotic (biosphere)
and abiotic (lithosphere, atmosphere and
hydrosphere) compartments of Earth.

3.  CYCLE – is a series of change which comes
back to the starting point and which can be
repeated
 *GASEOUS CYCLE
– transportation of matter through the
atmosphere
 *SEDIMENTARY CYCLES
- transportation of the matter through the
ground to water.

4. GASEOUS CYCLE

5. - are the combined processes, including:
photosynthesis, decomposition, and
respiration, by which carbon is a component
of various compound cycles between its
major reservoirs-the atmosphere, oceans
and living organisms.

6.  Carbon moves from the atmosphere to plants. In
the atmosphere, Carbon is attached to Oxygen in a
gas called Carbon Dioxide (CO2). With the help of
the Sun, through the process of photosynthesis,
carbon dioxide is pulled from the air to make plant
food from carbon.
 Carbon moves from plants to animals. Through
food chains, the Carbon that is in the plants moves
to the animals that eat them. Animals that eat other
animals get the Carbon from their food too.

7.  Carbon moves from plants and animals to the
ground. When plants and animals die, their bodies,
wood and leaves decay bringing the Carbon into
the ground. Some become buried miles
underground and will become fossil fuels in millions
and millions of years.
 Carbon moves from living things to the atmosphere.
Each time you exhale, you are releasing Carbon
Dioxide Gas into the atmosphere. Animals and
plants get rid of the Carbon Dioxide Gas through
respiration.

8.  Carbon moves from fossil fuels to the atmosphere when
fuels are burned. When humans burn fossil fuels to
power factories, power plants, cars and trucks. Most of
the Carbon quickly enters the atmosphere as Carbon
Dioxide Gas. Each year, five and a half billion of Carbon
is release by burning fossil fuels, 3.3 billion tons enters
the atmosphere and most of the rest becomes
dissolved in seawater.
 Carbon moves from the atmosphere to the oceans. The
oceans and other bodies of water, soak up some
Carbon from the atmosphere.

10. -
- the continuous sequence of natural
processes by which nitrogen in the atmosphere
and nitrogenous compounds in the soil are
converted, as by nitrification and nitrogen
fixation, into substances that can be utilized by
green plants and then returned to the air and
soil as a result of denitrification and plant decay.

11.  Fixation: The conversion of atmospheric
nitrogen into nitrogenous compounds by
bacteria (Rhizobia) found in the root nodules of
legumes and certain other plants, and in the
soil.
 Assimilation: Plants take nitrogen from the
soil, by absorption through their roots in the
form of their nitrate ions or ammonium ions. All
nitrogen obtained by animals can be traced
back to the eating of plants.

12.  Ammonification: When a plant or animal dies, or
an animal expels waste, the initial form of nitrogen
is organic. Bacteria, or fungi in some cases, convert
the organic Nitrogen within the remains back into
Ammonium (NH4+).
 Nitrification: The oxidation of the Ammonium
compounds in dead organic material into nitrites
and nitrates by soil nitrobacteria, making Nitrogen
available to plants. Nitrosomonas species converts
ammonia to nitrites (NO2-). Nitrobacter species are
responsible for the oxidation of the nitrites into
nitrates (NO 3-).

13.  Denitrification: Process occurs when
nitrates (NO3-) reduced to gaseous nitrogen
(N2), as by bacterial action on soil.