Download NO 3

Document related concepts

Protein moonlighting wikipedia , lookup

Magnesium transporter wikipedia , lookup

Protein phosphorylation wikipedia , lookup

Protein wikipedia , lookup

Protein (nutrient) wikipedia , lookup

Intrinsically disordered proteins wikipedia , lookup

Protein structure prediction wikipedia , lookup

Proteolysis wikipedia , lookup

Nitrogen cycle wikipedia , lookup

Transcript
N2
Lightning and the addition of
fertlisers also adds nitrates to soil
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Which
can be
taken
back up
by plants
and made
into
proteins
Animals get their
protein by eating
Death and decay
NO3-
Bacteria break down the protein into nitrates
Denitrifying bacteria
use nitrates and release
nitrogen into the air
80 % of the atmosphere is
made up of nitrogen gas
N2
nitrogen gas is very
unreactive
and very few organisms can
extract it from the air
Nitrogen is essential for all organisms as it
is needed to make proteins
Some terms you need to know
first:
•
•
•
•
•
•
N2
NH4+
NH3
NO2NO3NO2
Nitrogen
Ammonium
Ammonia
Nitrite
Nitrate
Nitrogen oxide
Plants can easily make
carbohydrates like sugars and
starches
+
+
NO3-
nitrate ions need to be
added to carbohydrates
to make amino-acids
Amino
acid
+
NO3-
nitrate ions need to be
added to carbohydrates
to make amino-acids
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
Amino
acid
The amino-acids are joined together in chains to make
polypeptides
But where does the nitrate come from?
But where does the nitrate come from?
But where does the nitrate come from?
Certain bacteria are able to take atmospheric
nitrogen and “fix” it into nitrate ions
N2
N2
N2
N2
NO3
-
N2
NO3
These nitrogen fixing bacteria are
either free living in the soil...
-
Or live in special nodules in
the roots of plants
These nitrogen fixing bacteria are
either free living in the soil...
Or live in special nodules in
the roots of plants
These nitrogen fixing bacteria are
either free living in the soil...
Or live in special nodules in
the roots of plants
These nitrogen fixing bacteria are
either free living in the soil...
Or live in special nodules in
the roots of plants
These nitrogen fixing bacteria are
either free living in the soil...
Or live in special nodules in
the roots of plants
These nitrogen fixing bacteria are
either free living in the soil...
NO3
-
NO3
-
The nitrate in the soil or in the root
nodules can then be used by the plant
to make proteins
Bacteria also
help to recycle
the nitrogen that
has been made
into protein
After death...
And of course the
production of waste
compounds containing
nitrogen
Bacteria break down these
proteins and waste products
to release ammonia NH3
Bacteria break down these
proteins and waste products
to release ammonia NH3
protein
Bacteria break down these
proteins and waste products
to release ammonia NH3
protein
Bacteria break down these
proteins and waste products
to release ammonia NH3
protein
Bacteria break down these
proteins and waste products
to release ammonia NH3
NH3
protein
Bacteria break down these
proteins and waste products
to release ammonia NH3
NH3
The ammonia is further
broken down by Nitrifying
bacteria to release nitrates
NH3
NO3The ammonia is further
broken down by Nitrifying
bacteria to release nitrates
Unfortunately some
of the nitrates in the
soil end up back as
nitrogen in the
atmosophere...
Nitrates
Nitrates
N2
Denitrifying bacteria
use nitrates and release
nitrogen into the air
Nitrates
Putting it all
together
into a
cycle...
N2
N2
N2
N2
Nitrates
Nitrogen fixing
bacteria in soil and
nodules of plants
N2
Nitrates
Nitrogen fixing
bacteria in soil and
nodules of plants
N2
NO3-
Nitrogen fixing
bacteria in soil and
nodules of plants
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Animals get their
protein by eating
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Animals get their
protein by eating
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Animals get their
protein by eating
Death and decay
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Animals get their
protein by eating
Death and decay
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Animals get their
protein by eating
Death and decay
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Animals get their
protein by eating
Death and decay
Bacteria break down the protein into nitrates
NO3-
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Animals get their
protein by eating
Death and decay
NO3Bacteria break down the protein into nitrates
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Which
can be
taken
back up
by plants
and made
into
proteins
Animals get their
protein by eating
Death and decay
NO3-
Bacteria break down the protein into nitrates
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Which
can be
taken
back up
by plants
and made
into
proteins
Animals get their
protein by eating
Death and decay
NO3-
Bacteria break down the protein into nitrates
N2
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Which
can be
taken
back up
by plants
and made
into
proteins
Animals get their
protein by eating
Death and decay
NO3-
Bacteria break down the protein into nitrates
N2
Lightning and the addition of
fertlisers also adds nitrates to soil
NO3Nitrates are made
into proteins in plants
Nitrogen fixing
bacteria in soil and
nodules of plants
Which
can be
taken
back up
by plants
and made
into
proteins
Animals get their
protein by eating
Death and decay
NO3-
Bacteria break down the protein into nitrates
Denitrifying bacteria
use nitrates and release
nitrogen into the air
Stages in N cycle
•
•
•
•
•
•
Nitrogen fixation
Use of Nitrates by plants
Assimilation by animals
Decomposition and ammonification
Nitrification
Denitrification
• NITROGEN from the air is converted into NITRATES by
NITROGEN FIXATION 4 ways:
1. Free living NITROGEN FIXING BACTERIA (Rhizobium) found in
the soil.
2. NITROGEN FIXING BACTERIA (Rhizobium) found in the roots of
some plants (leguminous). The rhizobium use an enzyme called
nitrogenase which converts N2 gas into ammonium ions NH4+. They
can only do this if they have 1). a supply of N2, 2). A supply of ATP
3).anaerobic conditions (no oxygen).
3. Fixation in the atmosphere -lightning. The energy from lightning
causes the N2 and O2 to react to form nitrogen oxides. These
dissolve in the rain and fall onto the ground.
4. Fixation by Harber process. This is when N2 and H2 gases are
reacted together to produce ammonia. This ammonia is converted
into ammonium nitrate, which is the most widely used inorganic
fertiliser.
Use of fixed nitrogen by plants
• In legumes the fixed nitrogen produced by the Rhizobium in
their root nodules is used to make amino acids. This is
distributed to all areas of the plant to make proteins.
• Some plants take up nitrate ions (NO3-) from the soil by active
transport. This is then converted to nitrite (NO2-), then
ammonia, and then amino acids e.g.
• NO3(Nitrate)
NO2(nitrite)
NH3
(ammonia)
• So plants use nitrates to make amino acids.
amino acids
(amino acids)
Assimilation of nitrogen
• Animals get their nitrogen from the proteins they eat.
• Proteins are broken down into amino acids during digestion.
• The amino acids are then built up again into proteins in cells
during protein synthesis.
Protein
amino acids
proteins
• Excess amino acids (any surplus protein in our diet) is
deaminated in the liver and is excreted in urea as urine.
Excess amino acids
urea
urine
Decomposition and Ammonification
• Decomposers gradually break down the protein in dead plants
and animals into amino acids – decomposition.
• Decomposers include bacteria and fungi which produce protease
enzymes.
• They use some of the amino acids for their own growth.
• The rest is broken down into ammonia.
• Ammonia is also produced from the urea in animal urine.
• The production of ammonia is called ammonification.
Nitrification
• The ammonia in the soil is then converted into nitrite ions (NO2-)
and then nitrate (NO3-) ions by nitrifying bacteria. (Nitrosomanus
and Nitrobacter).
Denitrification
• Dentrifying bacteria reverse the nitrogen fixation process.
• They convert nitrates back into nitrogen gas.
• Found in sewage treatment, compost heaps and wet soils.
What is the role of these
bacteria in the N cycle?
• 1. Nitrogen fixing (Rhizobium).
• 2. Nitrifying bacteria - Nitrosomanus
• 3. Nitrifying bacteria - Nitrobacter.
• 4. Dentrifying.
What is the role of these
bacteria in the N cycle?
• 1. Nitrogen fixing (Rhizobium).
Convert Nitrogen gas into organic nitrates in
soil and plants.
• 2. Nitrifying bacteria - Nitrosomanus
Convert ammonium into nitrites
• 3. Nitrifying bacteria - Nitrobacter.
Convert nitrites into nitrates
• 4. Dentrifying.
Convert nitrates into Nitrogen gas.
Stages in N cycle – breifly summarise each one:
1. Nitrogen fixation
2. Use of Nitrates by plants
3. Assimilation by animals
4. Decomposition and Ammonification
5. Nitrification
6. Denitrification
•
•
•
•
•
•
–
–
Nitrogen Fixation: converts gaseous nitrogen (N2) into ammonia (NH3).
Certain bacterial species, both aerobic and anaerobic, carry out this
conversion.
Nitrification: only certain bacteria, the nitrifying bacteria, can use NH3 as an
energy source. The reaction occurs in two steps:
Nitrosomonas bacteria convert ammonia (NH3) to nitrite (NO2-)
Nitrobacter bacteria convert nitrite (NO2-) to nitrate (NO3-)
Denitrification: bacteria that can respire anaerobically will convert nitrate
(NO3-) to nitrite (NO2-). Note that nitrate is now serving as an electron
acceptor. Some anaerobic respirers can also use nitrite (NO2-), converting it
further into nitrous oxide (NO), nitrogen dioxide (N2O), and ultimately
nitrogen gas (N2).
Assimilation: ammonia can be directly assimilated into organic compounds
inside cells, producing amino groups (-NH2).
Excretion: during excretion, fermentation, and other catabolic processes,
excess amino groups (-NH2) are released, ultimately producing ammonia
(NH3).
Assimilatory Nitrate Reduction: since nitrate (NO3-) is far more common
than ammonia, many organisms can only acquire nitrogen in the form of
nitrate. They must reduce nitrate to form the amino groups needed for
metabolism. This process, which superficially resembles nitrate reduction by
anaerobic respiration, is entirely different.
Reference:
http://www.slideshare.net/shabeelpn/nitrogen-cycle-3614281