Presentation on nitrogenfixation and it's type, Carbon cycle.

1. NITROGEN FIXATION,
NITROGEN AND
CARBON CYCLE
By: Saloni

2. NITROGEN FIXATION
 Nitrogen fixation is a process by which nitrogen in the Earth's
atmosphere is converted into ammonia (NH3) or other molecules
available to living organisms. Atmospheric nitrogen or molecular
dinitrogen (N2) is relatively inert: it does not easily react with other
chemicals to form new compounds. The fixation process frees
nitrogen atoms from their triply bonded diatomic form, N≡N, to be
used in other ways.
 Nitrogen fixation is carried out naturally in the soil by nitrogen
fixing bacteria such as Azotobacter. Some nitrogen-fixing bacteria
have symbiotic relationships with some plant groups,
especially legumes. Looser relationships between nitrogen-fixing
bacteria and plants are often referred to as associative or non-
symbiotic, as seen in nitrogen fixation occurring on rice roots.

7. The nitrogen cycle is the biogeochemical cycle by
which nitrogen is converted into multiple chemical forms as it
circulates among the atmosphere, terrestrial, and marine
ecosystems. The conversion of nitrogen can be carried out
through both biological and physical processes. Important
processes in the nitrogen cycle
include fixation, ammonification, nitrification, and denitrification.
The majority of Earth's atmosphere (78%) is nitrogen,[1] making
it the largest source of nitrogen. However, atmospheric nitrogen
has limited availability for biological use, leading to a scarcity of
usable nitrogen in many types of ecosystems.
NITROGEN CYCLE

8. The nitrogen cycle is of particular interest
to ecologists because nitrogen availability can affect
the rate of key ecosystem processes,
including primary production and decomposition.
Human activities such as fossil fuel combustion, use
of artificial nitrogen fertilizers, and release of nitrogen
in wastewater have dramatically altered the global
nitrogen cycle.

10. CARBON CYCLE
The carbon cycle is the biogeochemical cycle by
which carbon is exchanged among
the biosphere, pedosphere, geosphere, hydrosphere,
and atmosphere of the Earth. Carbon is the main component of
biological compounds as well as a major component of many
minerals such as limestone. Along with the nitrogen cycle and
the water cycle, the carbon cycle comprises a sequence of
events that are key to make Earth capable of sustaining life. It
describes the movement of carbon as it is recycled and reused
throughout the biosphere, as well as long-term processes
of carbon sequestration to and release from carbon sinks.

11. The carbon cycle was initially discovered by Joseph
Priestley and Antoine Lavoisier, and popularized by Humphry
Davy.
The global carbon cycle is now usually divided into the following major reservoirs
of carbon interconnected by pathways of exchange
•The atmosphere
•The terrestrial biosphere
•The oceans, including dissolved inorganic carbon and living and non-living
marine biota
•The sediments, including fossil fuels, fresh water systems and non-living organic
material.
•The Earth's interior, carbon from the Earth's mantle and crust. These carbon
stores interact with the other components through geological processes
The carbon exchanges between reservoirs occur as the result of various chemical,
physical, geological, and biological processes. The ocean contains the largest
active pool of carbon near the surface of the Earth. The natural flows of carbon
between the atmosphere, ocean, terrestrial ecosystems, and sediments is fairly
balanced, so that carbon levels would be roughly stable without human influence.