Activity #18: Activity #18: Cycles of Cycles of MatterMatter

EQEQ• How do Earth’s biotic and abiotic factors

interact to shape ecosystems and affect the survival of organisms over time?

• Why is the cycling of matter important to life on earth?

Challenge QuestionChallenge Question• Describe how matter cycles through an

ecosystem.

VocabularyVocabulary• Biogeochemical cycle• Denitrification• Nitrogen fixation

Four Main Elements of Four Main Elements of Living Things:Living Things:

• CHON• Make up:

o Watero Carbso Lipidso Nucleic acidso Proteins

Energy & MatterEnergy & Matter• Energy flows in a one way direction starting from

the sun o It is not recycled

• Matter is recycled through the biosphere

Matter is Recycled Within and Matter is Recycled Within and

Between EcosystemsBetween Ecosystems• This is different than the one-way flow of energy

through an ecosystem• Biogeochemical Cycles- process in which

elements, chemical compounds (water and nutrients), and other forms of matter are passed from one organism to another and from one part of the biosphere to another

Processes in Processes in Biogeochemical Cycles Biogeochemical Cycles

can be… can be… • Biological- cellular respiration,

photosynthesis, decomposition, nitrogen fixation, etc.

• Geological- erosion, rock formation, heat and pressure from the earth

• Chemical- formation of clouds/precipitation

• Physical- flow of running water• Human Activity- logging, deforestation,

burning fossil fuels, wastes, fertilizers

Energy and MatterEnergy and Matter• Energy powers the cycles of matter• Matter is transformed, never created or destroyed

The Water CycleThe Water Cycle• Water moves between oceans, atmosphere, and

land• Can be inside or outside of organisms

How does water vapor How does water vapor enter the atmosphere?enter the atmosphere?

• Evaporation• Transpiration• Combustion• Respiration

Once water vapor is in Once water vapor is in the atmosphere…the atmosphere…

• Condensation• Precipitation• Runoff• Groundwater

Also use evaporation

Nutrient CyclesNutrient Cycles• The cycling of carbon, nitrogen, and phosphorus

through organisms and the environment are especially important

The Carbon CycleThe Carbon Cycle• Carbon is a major

component of all organic compounds

• Found in some inorganic compounds o Example: calcium

carbonate (CaCO3) – molecule that is part of animal skeletons

o Example: carbon dioxide (CO2) - major part of the atmosphere and necessary for photosynthesis

Carbon & OxygenCarbon & Oxygen• Oxygen often cycles with carbon through the

biosphere, particularly due to photosynthesis and cellular respiration.

Makes Cell Walls

Fossil FuelsFossil Fuels• Fossil Fuels: Energy rich fuels (coal, oil, and

natural gas) created from carbon-containing compounds of ancient, dead forests, marine organisms, or other animals have been buried and transformed by pressure and heat.

ReservoirsReservoirs• Major reservoirs (locations of large

amounts) of carbon in the biosphere include the: o Atmosphereo Oceanso Rocks o Fossil Fuels o Forests

VideoVideo• bromothymol blue 3:20

The Nitrogen CycleThe Nitrogen Cycle• Nitrogen is required to make amino acids and

nucleic acids

Forms of NitrogenForms of Nitrogen• Different forms of nitrogen occur naturally in the

biosphere

• Nitrogen gas (N2)makes up 78% of earth’s atmosphere

• Ammonia (NH3), nitrate ions (NO3-), nitrite ions

(NO2-) are found in soil, in the wastes produced by

many organisms, and in dead and decaying organic matter.

• Dissolved nitrogen exists in several forms in the ocean and other large water bodies

Nitrogen gasNitrogen gas is the most is the most

abundant form of nitrogen on abundant form of nitrogen on

EarthEarth• Only a handful of organisms – certain types of

bacteria – can use this form directly• They “change” (=fix) the nitrogen into usable

forms• The usable forms can then be used by other

organisms • Thus, nitrogen-fixing bacteria are an essential

part of the nitrogen cycle

Nitrogen FixationNitrogen Fixation• Nitrogen Fixation: The conversion of Nitrogen

Gas (not usable) into Ammonia, Nitrates, and Nitrites (usable) by bacteria

• Some of these bacteria live in the soil whereas others live on the roots of certain plants called legumes (ex. peanuts, peas, soybeans)

• Bacteria are the driving force of the nitrogen cycle!

Available NitrogenAvailable Nitrogen• Once these forms of nitrogen are available,

primary producers can use them to make proteins and nucleic acids.

• Consumers eat the producers and reuse nitrogen to make their own nitrogen-containing compounds (and so on through the food web).

Nitrogen CycleNitrogen Cycle

Fertilizers Contain Fertilizers Contain Nitrogen & Nitrogen & PhosphorusPhosphorus

• Eutrophication: excess growth of algae due to increased levels of fertilizers in the watero Creates an algal bloomo Algae takes oxygen from

other organisms and may release toxins