Biogeochemical Cycles

Water CarbonNitrogen

4 ATOMS make up 95% of the body in most organisms

CARBONHYDROGEN

OXYGEN NITROGEN

The same molecules are passed around again and again within the biosphere in BIOGEOCHEMICAL CYCLES

WATER CYCLE= ___________________ HYDROLOGIC CYCLE

WHY IS WATER IMPORTANT?Makes up 60-70% of your body

Oxygen and Hydrogen are found in all the building blocks of cells carbohydrates, proteins,

nucleic acids, lipids

Hydrogen in H2O supplies protons (H+) & electrons For photosynthesis.

WATER CYCLE

evaporation

condensation

The evaporation of water from the surface of plant leaves = TRANSPIRATION

The return of water tothe surface in the form of rain, snow, sleet, hail, etc.= PRECIPITATION

WATER CYCLE

CARBON CYCLECO2 inatmosphere

CO2 inocean

4 main CARBON reservoirs in BIOSPHERE

CO2 inatmosphere

CO2 inOcean

1.In oceans as CO2 gas 2.In the atmosphere as

dissolved CO2 gas3.On land in organisms,

rocks, soil4. Underground as coal &

petroleum (fossil fuels) and calcium carbonate in rocks

Where does CO2 in atmosphere

come from?

CO2 inatmosphere

CO2 inOcean

1.Volcanic activity 2.Human activity (burning fossil

fuel) 3.Cellular respiration4.Decomposition of dead

organisms

WHY IS CARBON IMPORTANT?

Found in all the building blocks of cells: carbohydrates, proteins, nucleic acids, lipids

WHY IS CARBON IMPORTANT?

Carbon in CO2 provides the atoms for glucose production during photosynthesis the fuel that all living things depend on.

N2 in Atmosphere

NH3

NO3-

and NO2-

Section 3-3

NITROGEN CYCLE

WHY IS NITROGEN IMPORTANT?

Nitrogen bases make DNA and RNA

Adenine (nitrogen base) is used in ATP.

Makes AMINO part of amino acids in (proteins)

79% of the atmosphere is made up of NITROGEN gas

(N2)BUT we Can’t use the nitrogen gas

we breathe! The bond in N2 gas is so strong it can only be broken by Lighting, volcanic

activity, and a few special bacteria

Bacteria that live in the soiland in symbiotic relationships withplants called legumes, take nitrogen from the atmosphere and turn it into Ammonia, a form that is usable by plants.

THIS PROCESS IS CALLED

NITROGEN FIXATION

Other bacteria in the soil convertammonia into which plants can also use. The nitrogen we need for proteins, ATP, and nucleic acids comes from

the Food we eat

we breathe!

NITRATES (NO3- )

Not the air

and NITRITES (NO2

-)

N2 in Atmosphere

NH3

NO3-

and NO2-

Section 3-3

NITROGEN CYCLE

BIOLOGY; Miller and Levine; Prentice Hall; 2006

Bacteria that live in the soilalso carry out the reverse process

Nitrates/ Nitrates → Nitrogen gas.

THIS PROCESS IS CALLED

DENITRIFICATION