Biogeochemical CyclesBiogeochemical Cycles

Students will be able to…Draw and label the water, carbon, and nitrogen cycles and explain what happens in each part of the cycle.

Unit Objective

Matter and Living ThingsAn Introduction to Environmental

Chemistry

Brainstorm:What do living

things require?

TWANEtemperature

water

atmosphere

nutrients

energy

A TerrariumA terrarium represents the components of an ecosystem

and illustrates the fundamentals of energy flow.

Lightenergy

Chemicalenergy

Energy flow

Chemicalelements

Heatenergy

Bacteria,protists,and fungi

Ecosystems are supplied with a continual influx of energy from the sun

and Earth’s interior.

Is that enough?Is that enough?

Nope! So life on earth depends on the cycling of chemicals through the

ecosystem.

The Major Earth Systems

Geosphere – land, rocks, earth(Note: The surface land is called the lithosphere)

Hydrosphere – water (oceans, lakes, rivers…)

Atmosphere - air (78% N2, 21% O2)

Biosphere – all living and decomposing organisms

Cycling between them

Biogeochemical cycles is the flow of elements and compounds between biotic (living) components and abiotic (nonliving) components.

* reservoirs (or sinks)

Biogeochemical Cycles

compartments that store matter

WaterCycle

http://www.brainpop.com/science/earthsystem/watercycle/

Terms• Evaporation – liquid to a gas from the surface of

a liquid• Condensation – gas collecting into clouds of

water vapor• Precipitation – rain, sleet, or snow • Transpiration – evaporation of water from leaves• ground water – water that has seeped

underground• Aquifer– water trapped and stored underground• Run off – water that follows the slope of land

down to rivers, lakes and oceans

Interesting Facts about Water

• There is a constant amount of water on and in the earth.

• Only 3% of the water is “fresh” • 70% of fresh water is frozen in glaciers.

We have energy and water – now what nutrients do we need?

Only about 24 elements!

Six of them are macronutrients.

The rest are micronutrients.Ex: Calcium, Magnesium

We need them in large quantities!

We need them in large quantities!

What are the BIG SIX???

CHNOPS

hydrogen

Elements that make up Life!!

The Carbon CycleCARBON

So what is carbon in the real world?

• Main ingredient in all organic molecules • Used by plants in photosynthesis • Used to compose carbon dioxide and all

macromolecules• Graphite or diamond!

Can you name all three? Think

back to Sports and Human

Performance!

How do you think the levels of carbon stay in check in the

environment?

How do you think the levels of carbon stay in check in the

environment?

The return of CO2 to the atmosphere

by respiration closely balances its

removal by photosynthesis.

PhotosynthesisPhotosynthesis

Respiration

Respiration

Respiration

The Carbon Cycle

Play the Carbon Cycle Game - http://www.windows2universe.org/earth/climate/carbon_cycle.html

Continual movement of carbon atoms through organisms, oceans, atmosphere &

crust

The Carbon Cycle

Atmosphere

as CO2

Hydrosphere

as CO2

Biosphere

Geosphere

as proteins, sugars,

As limestone fossils & fossil fuel

Where do we find the MOST carbon dioxide?

90% of Carbon Dioxide is stored in the ocean reservoir!

What disrupts this balance?

What disrupts this balance?

The burning of fossil fuels!

Global Warming is a result of the excess CO2 in the atmosphere

http://www.brainpop.com/science/earthsystem/carboncycle/

Combustion Reaction:CH4 + O2 CO2 + H2O

Nitrogen – The Nitrogen Cycle

http://www.brainpop.com/science/earthsystem/nitrogencycle/

Air (N2) Nitrifying Bacteria Plants Animals Decomposers

Denitrifying Bacteria Air (N2)

Key Concepts

• Nitrogen in the soil (think fertilizer and manure) help plants grow.

• Plants get Nitrogen from the soil and excess nitrogen results in excess growth (to a point)

• Crop rotation keeps the nitrogen levels in the soil at healthy.

• Nitrogen is needed to make proteins – we get it by eating plants or eating animals that eat plants.

Bacteria are the Stars!

• Bacteria take the nitrogen out of the air and put it in the soil

• Other bacteria take the nitrogen out of the soil and puts it in the air

• Without bacteria there would be no nitrogen cycle.

What happens when humans disrupt the Nitrogen Cycle?

Algae blooms from fertilizer runoff into lakes and streams – These use up all the oxygen

Infertile land from using all the nitrogen up (this is why we have crop rotation)

Acid Rain from polluting gases

Check for Understanding:Think, Pair, Share

What would happen if all the decomposers went on “strike” and stopped working?

Which cycles would it affect and how?

Connection to

Space?These biogeochemical cycles is part of what

makes a planet habitable