
New Biogeochemical Cycle: The Nitrogen
Cycle.
Copyright © 2010 Ryan P. Murphy
• What will be studying a whole lot of in the
next few days?
Copyright © 2010 Ryan P. Murphy
• What will be studying a whole lot of in the
next few days?
Copyright © 2010 Ryan P. Murphy
• What will be studying a whole lot of in the
next few days?
Copyright © 2010 Ryan P. Murphy
• What will be studying a whole lot of in the
next few days?
Copyright © 2010 Ryan P. Murphy
• What will be studying a whole lot of in the
next few days?
Copyright © 2010 Ryan P. Murphy
• What will be studying a whole lot of in the
next few days?
Copyright © 2010 Ryan P. Murphy
• What will be studying a whole lot of in the
next few days?
Copyright © 2010 Ryan P. Murphy
• What will be studying a whole lot of in the
next few days?
Copyright © 2010 Ryan P. Murphy
• Yes, We will be studying concepts that
have a lot to do with waste.
Copyright © 2010 Ryan P. Murphy

Nitrogen Cycle: The circulation of nitrogen.
Copyright © 2010 Ryan P. Murphy

Nitrogen Cycle: The circulation of nitrogen.
Copyright © 2010 Ryan P. Murphy

Nitrogen Cycle: The circulation of nitrogen.
Copyright © 2010 Ryan P. Murphy

Nitrogen Cycle: The circulation of nitrogen.
Copyright © 2010 Ryan P. Murphy
• Video! The goal will be to try and make some
sense out this confusing video.
Copyright © 2010 Ryan P. Murphy
• Video! The goal will be to try and make some
sense out this confusing video.
– We will watch it again at the end of class to see if
we understand any of it. It’s wacky.
Copyright © 2010 Ryan P. Murphy
• Video! The goal will be to try and make some
sense out this confusing video.
– We will watch it again at the end of class to see if
we understand any of it. It’s wacky.
– http://www.youtube.com/watch?v=tSzLQojOItg&f
eature=iv&src_vid=Hghru0O7dDs&annotation_id
=annotation_151343
Copyright © 2010 Ryan P. Murphy
• Everyone take a deep breath in and then
breathe out.
– 78% of what you just breathed in was Nitrogen
N2 gas
– 78% of what you exhaled was… Nitrogen N2
gas.
Copyright © 2010 Ryan P. Murphy
• Everyone take a deep breath in and then
breathe out.
– 78% of what you just breathed in was Nitrogen
N2 gas
– 78% of what you exhaled was… Nitrogen N2
gas.
Copyright © 2010 Ryan P. Murphy
• Everyone take a deep breath in and then
breathe out.
– 78% of what you just breathed in was Nitrogen
N2 gas
– 78% of what you exhaled was… Nitrogen N2
gas.
Copyright © 2010 Ryan P. Murphy
• Everyone take a deep breath in and then
breathe out.
– 78% of what you just breathed in was Nitrogen
N2 gas
– 78% of what you exhaled was… Nitrogen N2
gas.
Copyright © 2010 Ryan P. Murphy
• Nitrogen in the atmosphere is N2 gas which is
doesn’t bond well with other molecules.
Copyright © 2010 Ryan P. Murphy
• Nitrogen in the atmosphere is N2 gas which is
doesn’t bond well with other molecules.
– Nitrogen forms triple bonds with itself.
Copyright © 2010 Ryan P. Murphy
• Nitrogen in the atmosphere is N2 gas which is
doesn’t bond well with other molecules.
– Nitrogen forms triple bonds with itself.
Copyright © 2010 Ryan P. Murphy
• Nitrogen in the atmosphere is N2 gas which is
doesn’t bond well with other molecules.
– Nitrogen forms triple bonds with itself.
Copyright © 2010 Ryan P. Murphy
• Nitrogen in the atmosphere is N2 gas which is
doesn’t bond well with other molecules.
– Nitrogen forms triple bonds with itself.
Copyright © 2010 Ryan P. Murphy
• When nitrogen is “fixed”, it’s bonds are split with the
other nitrogen. Now it has three arms to make new
friends,
Copyright © 2010 Ryan P. Murphy
• When nitrogen is “fixed”, it’s bonds are split with the
other nitrogen. Now it has three arms to make new
friends like oxygen.
Copyright © 2010 Ryan P. Murphy
• When nitrogen is “fixed”, it’s bonds are split with the
other nitrogen. Now it has three arms to make new
friends like oxygen.
Copyright © 2010 Ryan P. Murphy
• When nitrogen is “fixed”, it’s bonds are split with the
other nitrogen. Now it has three arms to make new
friends like oxygen (NO2)
Bacteria
Copyright © 2010 Ryan P. Murphy
• Rain and precipitation bring the atmospheric
Nitrogen to the ground.
• Rain and precipitation bring the atmospheric
Nitrogen to the ground.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Nitrogen fixing bacteria in the soil and on the
root nodules of plants can fix the nitrogen.
– Fix means change its form so a plant can use it.
• Plants can now use this new molecule to get the
nitrogen they need to build proteins so they can
grow, repair, and reproduce.
Oxygen
Copyright © 2010 Ryan P. Murphy
• Plants can now use this new molecule to get the
nitrogen they need to build proteins so they can
grow, repair, and reproduce.
– With the help of nitrogen fixing bacteria
Oxygen
Copyright © 2010 Ryan P. Murphy
• Plants can now use this new molecule to get the
nitrogen they need to build proteins so they can
grow, repair, and reproduce.
– With the help of nitrogen fixing bacteria
Oxygen
Copyright © 2010 Ryan P. Murphy
• Plants can now use this new molecule to get the
nitrogen they need to build proteins so they can
grow, repair, and reproduce.
– With the help of nitrogen fixing bacteria
Oxygen
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• Eventually, plants and animals die.
• Ammonia (NH3) / Decay / Waste
• When plants and animals die.
– Nitrifying bacteria break down the nitrogen in
their tissues. (Nitrites NO2)
• When plants and animals die.
– Nitrifying bacteria break down the nitrogen in
their tissues. (Nitrites NO2)
• When plants and animals die.
– Nitrifying bacteria break down the nitrogen in
their tissues. (Nitrites NO2)
• Denitrifying bacteria can also change the
NH3 Nitrate back to N2 Nitrogen gas
• When the nitrogen is denitrified, it then bonds with
another nitrogen to form inert N2 gas in the
atmosphere until the cycle repeats.
Copyright © 2010 Ryan P. Murphy
• When the nitrogen is denitrified, it then bonds with
another nitrogen to form inert N2 gas in the
atmosphere until the cycle repeats.
“We now get to
hang out in the
atmosphere for
a long time.”
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• All life requires nitrogen-compounds, e.g.,
proteins and nucleic acids.
• Air, which is 79% nitrogen gas (N2), is the major
reservoir of nitrogen.
• But most organisms cannot use nitrogen in this
form.
• Plants must secure their nitrogen in "fixed" form,
i.e., incorporated in compounds such as:
– nitrate ions (NO3−)
– ammonia (NH3)
– urea (NH2)2CO
• Animals secure their nitrogen (and all other)
compounds from plants (or animals that have
fed on plants).
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Nitrification: Plants with bacteria take up
nitrogen.
– Decay: Passes on through eating / waste.
– Denitrification: Nitrogen returned to the air by
bacteria.
• Happens with poor soil management.
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Nitrification: Plants with bacteria take up
nitrogen.
– Decay: Passes on through eating / waste.
– Denitrification: Nitrogen returned to the air by
bacteria.
• Happens with poor soil management.
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Nitrification: Plants with bacteria take up
nitrogen.
– Decay: Passes on through eating / waste.
– Denitrification: Nitrogen returned to the air by
bacteria.
• Happens with poor soil management.
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Nitrification: Plants with bacteria take up
nitrogen.
– Decay: Passes on through eating / waste.
– Denitrification: Nitrogen returned to the air by
bacteria.
• Happens with poor soil management.
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Plants with the help of bacteria take up nitrogen.
– Decay: Passes on through eating / waste.
– Denitrification: Nitrogen returned to the air by
bacteria.
• Happens with poor soil management.
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Plants with the help of bacteria take up nitrogen.
– Decay and waste passes on nitrogen
– Denitrification: Nitrogen returned to the air by
bacteria.
• Happens with poor soil management.
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Plants with the help of bacteria take up nitrogen.
– Decay and waste passes on nitrogen
– Denitrification: Nitrogen returned to the air by
bacteria.
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Plants with the help of bacteria take up nitrogen.
– Decay and waste passes on nitrogen
– Denitrification: Nitrogen returned to the air by
bacteria.
Copyright © 2010 Ryan P. Murphy
• Four processes participate in the cycling of
nitrogen through the biosphere:
– Nitrogen fixation: Break apart N2 so it can join to
other atoms and be used.
– Plants with the help of bacteria take up nitrogen.
– Decay and waste passes on nitrogen
– Denitrification: Nitrogen returned to the air by
bacteria.
• Happens with poor soil management.
Copyright © 2010 Ryan P. Murphy
• This is an example of poor soil conservation
methods which leads to soil nutrient depletion.
Copyright © 2010 Ryan P. Murphy
• This is an example of poor soil conservation
methods which leads to soil nutrient depletion.
– The lost nitrogen in this runoff will be denitrified by
bacteria back to the atmosphere .
Copyright © 2010 Ryan P. Murphy
• This is an example of poor soil conservation
methods which leads to soil nutrient depletion.
– The lost nitrogen in this runoff will be denitrified by
bacteria back to the atmosphere .
Copyright © 2010 Ryan P. Murphy
• Manmade fertilizers also puts nitrogen into
the soil. (Ammonia NH3)
Copyright © 2010 Ryan P. Murphy
• Manmade fertilizers also puts nitrogen into
the soil. (Ammonia NH3)
– Excess / poor management of nitrogen
can result in pollution.
Copyright © 2010 Ryan P. Murphy
• Manmade fertilizers also puts nitrogen into
the soil. (Ammonia NH3)
– Excess / poor management of nitrogen
can result in pollution.
Copyright © 2010 Ryan P. Murphy
• Manmade fertilizers also puts nitrogen into
the soil. (Ammonia NH3)
– Excess / poor management of nitrogen
can result in pollution.
Copyright © 2010 Ryan P. Murphy