3.4 Biogeochemical Cycles 2

Biogeochemical Cycles

Ms. Havu, 10/10/23

Nutrients, like all other matter, can never be created or destroyed, only transformed.

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Biogeochemical cycles = nutrient cycles

Nutrient cycling

They are: carbon, oxygen, nitrogen, and phosphorus.

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The water cycle also plays a part in all biogeochemical cycles

Four nutrients cycle through all of Earth's spheres and organisms

Multiple Select

Why are nutrients important to organisms?

• Because organisms require nutrients for life processes.

• Because without nutrients, organisms would die.

• Because nutrients help organisms grow.

• Because nutrients give organisms energy.

CARBON:

Plants and animals need carbon to survive

What isn't used is released back into the atmosphere through cellular respiration

Is used by consumers and decomposers in their life processes

Plants pull in carbon dioxide through photosynthesis and produce oxygen and carbohydrates

Helps plants create food

​Cellular respiration:

allows organisms to release the chemical energy of ​sugars- it fuels life​

​Human impact:

-releasing a lot of carbon into the atmosphere by digging up and burning fossil fuels​

-getting rid of plants that could remove carbon from atmosphere​

​Undiscovered carbon sink:

-There is ​1.2-2.2 billion tons of carbon dioxide unaccounted for

-Humans release a lot of carbon dioxide, more than what has been found in atmosphere and oceans​

-all of that carbon has to go somewhere​

Multiple Choice

Who uses photosynthesis to turn carbon dioxide, sunlight, and water into oxygen and sugar?

• Mammals

• Birds

• Reptiles

• Plants

PhosPhorus:

Phosphorous ROCKS!

Mostly in the lithosphere (rocks) and oceans

Where it is stored:

-Used by DNA and RNA

-​Helps make protein to maintain and repair cells and tissue

Important in Plants and animals

Human impact

Remember the article about the Dead Zone in the Gulf of Mexico?

Creates overgrowth of plants in water

Because there are so many plants, there is less oxygen available in the water​

We release lots of phosphorus

Through mining rocks and minerals

We consume it when drinking water or eating plants or animals ​containing it

We obtain Phosphorus

Multiple Choice

Where is most of the phosphorus in the environment found?

• The atmosphere

• The lithosphere

• The biosphere

NItrogen:

Very scarce in lithosphere, hydrosphere, and organisms

Mostly in the atmosphere

-Used in proteins and DNA and RNA

-Essential for plant growth​

important in plants and animals

Nitrogen fixation

Lightning strikes also fix nitrogen, shocking!

Allows humans to fix nitrogen artificially

​Done by synthesizing ammonia

haber-bosch process

Crops that increase the amount of usable nitrogen in soil

thanks to nitrogen fixing bacteria​

legumes

Denitrifying bacteria complete the nitrogen cycle by converting nitrates in soil or water back to natural gas

Denitrification

When bacteria in soil take waste from decomposers to convert ammonium ions to nitrite ions, then into nitrate ions.

nitrification

nitrification and denitrification

Plants take up the nitrate ions from nitrifying bacteria

Multiple Choice

Where is nitrogen mostly found?

• The atmosphere

• The lithosphere

• The biosphere

• The hydrosphere

Open Ended

How have you participated in one of these cycles (carbon, phosphorus, nitrogen) today?

Open Ended

What's one question you still have about biogeochemical cycles?