Energy Flow through Organisms
Name: Lindsay Husta
Title
of Lesson:
Energy Flow through Organisms
Date
of Lesson:
Length
of Lesson:
55 minutes
Description
of Class:
Name of Course: Biology
Grade Level: 9-12
Honors or Regular: Both
Source of the Lesson:
Me
TEKS
Addressed:
(2)
Scientific
processes. The student uses scientific inquiry methods during field and
laboratory investigations. The student is expected to:
(D) communicate
valid conclusions; and
(E) construct
graphs, tables, maps, and charts using tools
including computers to organize, examine, and evaluate data.
(11) Science
concepts. The student knows that organisms maintain homeostasis. The
student is
expected to:
(D) summarize the role of microorganisms in
maintaining and
disrupting equilibrium including diseases in plants and animals and
decay in an
ecosystem.
(12) Science
concepts. The student knows that interdependence and interactions occur
within
an ecosystem. The student is expected to:
(A) analyze the flow of energy
through various cycles including the carbon, oxygen, nitrogen, and
water
cycles;
(D) identify and illustrate
that long-term survival of species is dependent on a resource base that
may be
limited; and
The
Lesson:
I.
Overview:
The students will construct the nitrogen cycle using clues about the pools and processes, read and illustrate a story about the nitrogen cycle, and discuss possible alterations to the cycle in the lakes they are studying.
II.
Performance or Learner
Objectives:
Students will be able to:
|
·
Draw the nitrogen cycle with
pools and processes that change N from one form to another. |
|
·
Classify pools as (a)biotic and (un)available. |
|
·
Classify processes as energy
releasing or requiring and oxic or anoxic. |
|
·
Hypothesize affects of various
changes in pool size on the nitrogen cycle. |
|
|
III.
Resources, materials, and
supplies needed:
Transparency or blackboard for
Common/Unique
Scissors
Paper
Colored pencils for illustrating
IV.
Safety considerations: Keep scissors pointing down
while walking with them
V.
Supplementary materials,
handouts:
·
“The exciting
cycle of nitrogen”
·
Board (may
need to be enlarged)
|
Teacher
Says/Does |
Student
Says/Does |
|
Engage: Common/unique
game with different forms of nitrogen. Mantra of the lesson: There are pools and processes.
Pools are forms nitrogen takes and can be described as (in)organic and (un)available. Processes
are chemical reactions that change one form to another. |
Writes
down a form of nitrogen that s/he doesn’t think any other group has. |
|
Evaluate: How many forms of nitrogen did they come up
with? Are they familiar with the common
naturally occurring forms. |
|
|
Explain: Mantra of the lesson: There are pools and processes.
Pools are forms nitrogen takes and can be described as (in)organic and (un)available. Processes
are chemical reactions that change one form to another. Make
sure the students are aware of the following forms of nitrogen: Nitrite (NO2), Nitrate (NO3), Nitrogen
gases (NO, N2O, N2), Ammonia (NH3), organic forms (a.a., proteins,
oil, coal) Pass
out the cards and game boards. Have
the students cut out the cards Classify
the types/forms of nitrogen into a cuadrat
of organic and inorganic vs available and
unavailable and have students write the information on each card. How
does the nitrogen get from one form to the other? We
can classify these reactions in two ways. Some
need oxygen and some need the absence of oxygen. An
environment with oxygen is called oxic. An environment with no oxygen is called
anoxic. Please
record the following information on your cards as you will need it. Assimilatory
nitrogen reduction, ammonification, and
nitrification happen in the presence of oxygen, while nitrogen fixation
and denitrification happen in anoxic
regions. Some
chemical reactions require energy while others release them. Think of those that require energy as being
big bowling balls that you have to lug up some stairs where as the
chemical reactions that release energy are like bowling balls at the
top of stairs that roll down with no work at all. Assimilatory
nitrogen reductionm, denitrification,
and nitrogen fixations are all like carrying a huge weight uphill while
nitrification is like rolling the ball down hill. Ammonification doesn’t use or release energy. Imagine yourself sitting at the top of a hill
painting your bowling ball. You have
changed it, but haven’t pushed it uphill or rolled it downhill. Spot
check students cards to make sure they have
been filling them out. |
Student cuts
out cards Students
write (in)organic and (un)available on each
form of nitrogen. Chemical
reactions Students
listen Students
write (an)oxic or presence/ absence of
oxygen on each chemical reaction card Students
write energy expended/released/ no change on
each chemical reaction card |
|
Evaluate:
Have students filled their cards. Do they
understand that reactions can be classified? If
they don’t compare processes to methods of travel: easy vs hard, with a machine or without. |
|
|
Explore: Mantra of the lesson: There are pools and processes.
Pools are forms nitrogen takes and can be described as (in)organic and (un)available. Processes
are chemical reactions that change one form to another. Now
we are going to use the clues on the cards to diagram the nitrogen
cycle. The pools or forms of nitrogen need
to be placed in the correct environmental conditions (oxic vs an oxic) and
in the organic or inorganic column. They
also need to be placed correctly with respect to the y-axis which
represents potential energy (where is the bowling ball). Then
you need to determine which process causes which form change. Use the energy and environmental clues we
wrote down. Use arrows to indicate
direction of reaction. |
Students
work in groups to determine the nitrogen cycle. They
place pools according to environment and use reaction reactants and
products to figure out if a pool is high in potential energy or low. |
|
Evaluate:
Are students able to figure out the nitrogen cycle? |
|
|
Elaborate: Mantra of the lesson: There are pools and processes.
Pools are forms nitrogen takes and can be described as (in)organic and (un)available. Processes
are chemical reactions that change one form to another. Have
students read “The Exciting Cycle of Nitrogen”
and create a comic book illustrating that story or another version
which is based on the nitrogen cycle. The
panes should include important places (forms of nitrogen) and methods
of travel (reactions) -Day
2- Have
students switch comics with other 2-3 other students.
Have people who created original stories share their
version. Students should check each other
for accuracy. Let’s
talk about our aquatic lake systems that we are studying.
What are the primary producers that are performing
assimilatory nitrogen reduction (nitrogen uptake)? Where
does ammonification take place? From
your research, what is eutrophication? What
are some effects? Where
do these extra nutrients come from? What
form of nitrogen is it? How
would pool sizes and processes change in eutrophic
vs oligotrophic
lakes? Using
your knowledge of the nitrogen cycle, what would you do to reduce human
impact on lakes? Hypothesize
about the nitrogen dynamics in the lakes they are studying from the
internet data. Give them time to write
about it and create nitrogen cycle diagrams as they are required for
their papers. |
Students
read story and create a comic book in groups of 3.
They are encouraged to create their own story. Students
share their books with others and check each other for accuracy of
portrayal. They are respectful of other
artistic interpretations and ideas. Phytoplankton,
algae, aquatic plants. All
eukaryotes-plants, animals, decaying matter… Addition
of nutrients increased
N and P, algal blooms, decreased DO, death of animals and plants,
bacterial bloom, further depletion of DO (anoxic environment),
stagnation and swamp formation Runoff
from fertilizers, organic waste NH3,
NO2, NO3 Any
number of logical scenarios could happen including: increased
assimilation due to influx of nutrients. Then
after things start dying, increased ammonification
due to decomposition. When things go to
anoxic conditions, most of the nitrogen cycling is through
nitrification, denitrification, and
N-fixing. Reduce
runoff and other nutrient input. Students
work on with their own lakes to decide what is going on in their system. They may also think about what went on in
their experiment. |
|
Evaluate: A little N cycle quiz in which
they take out a sheet of paper and tell me what they know.
By now they should be well versed in the mantra of the
lesson. Besides that any specific pool and
process names or type of organism which catalyzes the reaction would be
great. |
|
The
exciting cycle of nitrogen!!!
You awake with a tremendous headache and
the
unsettling feeling of having been here before.
With a Herculean strength you unglue eyelids, and when the world
comes
into focus, you realize that you have no idea where you are. Gradually, the gang of tiny jackhammers in
your skull quiet, and you realize that you are quite cold.
You get up, look around and espy a sign. “Ammonia”
it reads. You stare in disbelief. “Can it be true? Am
I really on this mountaintop
again? How did I get here this
time?” Suddenly you see a sled sitting
in the snow. You decide that a sled ride
would be the quickest way down, so you hop on.
The sled picks up speed. “Niiiiiiiitriiiiifiiiicaaaaaaaaaaation,”
you squeal delightedly on the ride. You
pass right through the tiny alpine hamlet(town)
of
Nitrite. However, the terrain flattens
out in the quaint
A brave soul! You chose the anoxic swamp
and ocean
sediments home to the ferocious cyanobacteria
and
nitrogen fixing bacteria. I hope you can
take the heat. Everything is strange
here. At first it’s a land of carnival
mirrors. You pass through the quaint
To scared of the swamp? Think you
can overpower the primary producer
monster? HA. Good
luck with that. Almost as soon as you veer
off into the
seemingly pleasant and well oxygenated soils and sediments of the
world, you
are sucked up the giant vacuum tube of a plant monster roots or if you
ended up
in the water column, a ferocious phytoplankton.
You are incorporated into an amino acid where you spend your
days as
part of a busy protein. And, when your
trusty protein is worked to exhaustion, it is simply hydrolysed
(broken apart). Broken down by Ammonification you are unneeded, and in fact
poisonous to
the primary producer monster, so it excretes you, on the top of a
tall, cold
mountain. It seem
familiar, but then you lose consciousness.
Go to the beginning.
|
(aka N uptake) NO3-àa.a., proteins By primary producers __________________ __________________ |
Organic Nitrogen Ex. Proteins ___________________ ___________________ |
Nitrogen Gases Ex. N2, NO2,
NO ___________________
___________________ |
|
N fixation N2àNH3 By bacteria __________________ __________________ |
Ammonification ProteinàNH3 Decomposition __________________ |
Nitrification NH3àNO2-àNO3- By bacteria ___________________ ___________________ |
|
Nitrite (NO2-) and
Nitrate (NO3-) __________________ |
Ammonia (NH4) __________________ __________________ |
Denitrification NO2- & NO3-àNH3 By bacteria ___________________ ___________________ |
