3.4 Nutrient Cycling

Anchor: BIO.B.4.2 Describe interactions & relationships in an ecosystem◦ BIO.4.2.3: Describe how matter recycles through

an ecosystem

Standards

Remember: living organisms are composed of organic matter:◦ Full of carbs, lipids, proteins & nucleic acids!

Ecology

How is matter cycled?◦ **Remember: there is a ONE-

WAY flow of energy through the ecosystem, but matter (organic stuff) must be recycled throughout the ecosystem!!*** Energy is moved through parts of an

ecosystem through biogeochemical cycles Ex: water, sulfur, phosphorus,

carbon, nitrogen cycles

nutrients

decomposers

ECOLOGY

Nutrients: molecules that an organism needs to sustain life◦ Used to build tissues and

carry out metabolism Ex: CHONPS

Ecology

nutrients

decomposers

Hydrologic Cycle◦ Importance

Every living thing requires WATER

Ecology

Hydrologic Cycle◦ Key Processes:

Evaporation: liquid gas Transpiration: evaporation

from plant leaves Condensation: gas liquid Precipitation: rain, sleet,

snow, hail Runoff: water moving

downhill into streams/rivers

Infiltration: water soaking into the soil

Ecology

Hydrologic Cycle

Ecology

http://earthguide.ucsd.edu/earthguide/diagrams/watercycle/

Evaporation

Condensation

PrecipitationTranspiration

Runoff

Carbon Cycle◦ Importance

Used in making living tissues and animal skeletons Regulates temperature in the atmosphere (carbon

dioxide) Plants photosynthesis pass along glucose in

food webs

Ecology

Carbon Cycle◦Key Processes:

Photosynthesis: how autotrophs produce glucose (food) while removing carbon dioxide from the air

CO2 + H2O + light C6H12O6 + O2

Cellular Respiration: how all organisms break down food to get ATP energy and release carbon dioxide in the air

C6H12O6 + O2 CO2 + H2O + ATP ATP is a molecule used for energy

Ecology

◦Decomposition: bacteria and fungi break down dead organisms and release their nutrients in the soil and carbon dioxide in the air

Creates fossil fuels with extreme pressure

◦Combustion: Burning of fossil fuels (coal, oil, natural gas) and trees releases carbon dioxide into the air and this can lead to global warming

Ecology

http://www.npr.org/2007/05/01/9943298/episode-1-its-all-about-carbon

CO2

Burning FF

CR by plants/animals

DecompositionFossil Fuel formation

PSBurning plants

Nitrogen Cycle:◦Importance:

All organisms require nitrogen to make amino acids that are used to build proteins

◦Forms of Nitrogen: Nitrogen Gas (N2): in atmosphere Ammonia (NH3), Nitrate (NO3

-), Nitrite (NO2

-): found in wastes & in decaying organisms

Ecology

Nitrogen Cycle:◦Key Processes: Nitrogen fixation: convert nitrogen gas

into ammonia N2 NH3

Performed by bacteria found in the soil or in roots of plants

Ecology

Nitrogen Cycle:◦Key Processes: Ammonification: ammonia (NH3) is

converted to nitrate (NO3-) and nitrite

(NO2-)

NH3 NO3-

NH3 NO2-

Done by bacteria in the soil

Ecology

OR

Nitrogen Cycle:◦Key Processes: Assimilation: plants use nitrates or nitrites made for them by the bacteria or animals consume nitrates and nitrites by eating plants Nitrogen is in organism and can be used to

make amino acids

Ecology

Nitrogen Cycle:◦Key Processes: Detrification: nitrates (NO3

-) are changed into nitrogen gas (N2) NO3

- N2

Nitrogen gas is released back into atmosphere

Ecology