Biogeochemical Cycle
of Oxygen
By River, Claudia, Brenna, and Helena
Steps:
1. Photosynthesis
2. Oxygen
3. Respiration
4. Carbon Dioxide
Photosynthesis
Photosynthesis is a reduction reaction
It adds oxygen gas to the air
Enormous quantities of oxygen are taken in by
plants and animals every day & returned to the
air by plants.
Oxygen: O2
Enormous amounts of oxygen are taken in by plants and animals
every day
Huge quantities of oxygen are returned to the air by plants.
These amount exactly balance so that overall the amount of
oxygen in the air stays the same.
Fun Fact: Oxygen is the most abundant of the biogeochemical
elements in the atmosphere and human body.
Respiration (Breathing)
Respiration is an oxidation reaction, which takes oxygen from the air or from
water.
It is the reverse of the Photosynthesis Formula →
breathe out carbon dioxide
breathe in oxygen,
Carbon Dioxide: CO2
●
Carbon dioxide is a product of the respiration cycle.
●
Carbon dioxide is released into the atmosphere
●
The release of carbon dioxide is then taken in by plants
along with water and sunlight to start the process of
photosynthesis.
Review Questions
❖ How do plants and humans benefit each other?
❖ Carbon dioxide is the production of what cycle?
❖ Along with carbon dioxide what other materials are used to start the process of
photosynthesis?
❖ What is the most abundant biochemical in the world?
Why is This Important
The Oxygen Cycle is important because without it we
would not be able to breath, and we would not have any plants on
earth. It’s the key to producing energy and between
photosynthesis and respiration. The process is dependent on the
other processes in the cycle. Without one you lose all the others.
This cycle is an example of steady state equilibrium.
Carbon
Cycle
Zoe
Julia
David
danny
Uses of Carbon
➢ Coal and Oil.
➢ Graphite.
➢ Key component of
steel.
➢ Carbon Fiber
Importance of Carbon
➢ All living things are made of carbon.
➢ Carbon is the fourth most abundant element
in the universe.
➢ Basis for life: the physical cycle of carbon
through the earth's biosphere, geosphere,
hydrosphere, and atmosphere;
Carbon Cycle
➢ Carbon is released
Simplified
by respiration and
burning of fossil
fuels.
➢ Carbon bonds with
oxygen in the
atmosphere.
➢ Plants pull Co2 from
Changes in the Carbon Cycle
➢ Carbon cycle has changed in response to
climate change.
➢ Ice ages slowed carbon cycle.
➢ Today, changes in the carbon cycle are
happening because of people. We perturb
the carbon cycle by burning fossil fuels and
How it should Work
➢ The geological carbon cycles takes place
over millions of years.
➢ Co2 density should never be gained in the
atmosphere.
➢ All carbon recycles through the system.
➢ Worldwide ecosystems exists in harmony.
Review Questions
➢ What are two uses for carbon?
➢ How have we affected the carbon cycle?
➢ What is the process called for converting Co2
to O2 in the cycle?
➢ Does carbon ever get lost in the cycle?
Sulfur Cycle
By: Haley, Chloe, Kaeleigh, and Finn
The cycle
1.
Sulfur is emitted in volcanic eruptions, hot springs, and the combustion and consumption of fossil fuels
2. Sulfur is released from the atmosphere in acidic precipitation, rain or snow
3. Sulfur is absorbed into both earth and water, oftentimes bonding with other elements like Mercury,
creating sulfates or fossil fuels
3a. Decomposing plants and animals add sulfur to the soil
3b. Sulfur is bonded into minerals (Pyrite and Gypsum) which when they reach the surface, are broken
down, the sulfur bonds with Hydrogen, which forms Hydrogen sulfide, (a gas) that rises into the atmosphere
1.
The plants absorb the sulfates from the soil, and fossil fuels are mined and consumed
Sulfur in the Atmosphere
Sulfur is emitted by the burning of fossil fuels, which emerged with the
industrialization of society. As our energy source is still mostly coal and fossil fuels,
sulfur is an element that has increased dramatically with the consumption and
combustion of fossil fuels. Sulfur is also the main contributor to acid rain, and as
sulfur increases, so the acid rain reflects this correlation, creating more damage to
the environment. This is an example of positive feedback.
Acid rain (and other precipitation)
Sulfur is normally released from the atmosphere in acid rain or snow. Acid rain’s
largest impact is on lakes and waterways, making them acidic, killing off the wildlife
and damaging the ecosystem. The acid rain also increases the holding capacity of
water for aluminum, which further deviates the mineral composition of the water
from the equilibrium.
Absorption
Sulfur is absorbed into the earth and water through the precipitation, bonding with
elements such as Mercury and Lead. These can bond with other compounds to
create minerals like Gypsum and Pyrite.
Gypsum and Pyrite, when exposed on the surface, (and heat as well) are broken
down, the sulfur bonds with Hydrogen, forming Hydrogen sulfide which rises to the
atmosphere.
Sulfur is also added to the soil through the decomposition of organic matter such as
the corpses of both plants and animals.
Mining and usage
Fossil fuels are constantly being mined for fuel, the combustion of which emits
more sulfur into the atmosphere. The fuel is used for jets, cars, and other forms of
transportation. Sulfur is also used in gunpowder, fireworks, and other forms of
explosives. Sulfur dioxide is used to bleach fabrics, and Sulfuric acid is a widely
used chemical.
Review questions
Name the consumptionist method of adding sulfur to the
atmosphere.
Name the harmful precipitation that contains sulfur.
Name one effect of acid precipitation.
What is one usage of sulfur or a sulfur bonded compound?
Describe the positive feedback cycle for sulfur.
The
Phosph
ate
Chemic
Thea, Avery, Emma
&al
Anna
Cycle
What is Phosphorus?
Phosphorus
Phosphate
Chemical Element (P)
Solidified form of Phosphate
Essential Nutrients for animals and
plants in cell development
Used in Fertilizers
Found in ATP, DNA, and lipids
Insufficient amounts of phosphorus
in soil can lead to decrease in
crops
Weathering
Phosphate is released from rocks in the form of ions when rocks are broken down
and exposed to rain and other forms of weather.
Consumption
Phosphate ions are absorbed through the soil by plants, and used to enrich them
as natural fertilizers. Animals then eat the plants and the phosphate is stored as
molecules such as DNA
Back to the
Earth
When a plant or animal dies, the phosphate is reintroduced to the soil and earth
below, and is broken down by bacteria into inorganic matter.
This process is called mineralisation
Completing the
Cycle
Phosphorus can find its way back to the ocean, where it can be incorporated into
the cycle again when fish and plants die and decompose. The Phosphorus can then
find it’s way back into the soil and starts over again.
Other Effects
Eutrophication
Biomagnification
Eutrophication is the nutrient buildup of
phosphate, as a result of excess amounts used
in fertilizers. When humans use too much
phosphate based fertilizers in their soil and for
their crops, the plants are not only packed with
excess nutrients, but the runoff ends up in
waterways and the ocean. Algae and bacteria
then eat this phosphate and experience intense
exponential growth, and uses up all the oxygen
in the ecosystem, possibly killing off the other
species and throwing the cycle off balance.
As phosphorus moves up in the cycle, this
process of biomagnification occurs; working
much like a food chain cycle.
Phosphate -> Algae -> Plankton -> Fish -> Human
By the time the fish is eaten by the human, the
percentage of phosphate has accumulated into
more than the original amount found in the algae
or plankton.
Ecological
Significance
For the phosphorus cycle to run
smoothly, it would be more effective
if humans didn’t use as much
phosphate based fertilizer in their
soil; this would reduce the amount
of phosphate getting sent back into
the ocean, and limiting the amount
of Eutrophication and
Biomagnification. With less
phosphate buildup in the cycle, the
balance of amount of chemicals per
organism would be more ideal.
Review Questions
How does Phosphorus come into and leave the cycle?
Is using phosphate based fertilizer a good or bad idea?
What happens when too much phosphorus is consumed by a plant or animal?
What is the role of eutrophication and biomagnification in the phosphorus cycle?
How does it affect other organisms?
Sources
http://www.shmoop.com/ecology/phosphorus-cycle.html
http://sciencelearn.org.nz/Contexts/Soil-Farming-and-Science/Science-Ideas-andConcepts/The-phosphorus-cycle
Image Source:
http://sciencelearn.org.nz/Contexts/Soil-Farming-and-Science/SciMedia/Images/The-phosphorus-cycle