Biogeochemical Cycles
I. Biogeochemical Cycles - Flow of chemical _____________________& compounds between living
organisms & the physical environment
Chemicals :
 Absorbed or ingested by organisms (__________________________)
 Returned to the soil, air, and water by:
1. ______________________________
3. _________________________________
2. ______________________________
4. _________________________________
Biogeochemical Processes
1. _______________________________________________________________________________
2. _______________________________________________________________________________
3. _______________________________________________________________________________
Biogeochemical Cycles & the Earth
A. Water Cycle
B. Carbon Cycle
C. Nitrogen
D. Sulfur
E. Phosphorus
Largest source of water on Earth = ____________________________________________________
Largest source of freshwater on Earth = ________________________________________________
Largest source of usable freshwater on Earth = ___________________________________________
Water Cycle Vocabulary Review
Evaporation
 Liquid water is heated by sun & changed to water vapor
Condensation
 Water vapor is cooled and turns to liquid water droplets
Precipitation
 Any form of water falling from the sky
Recharge
 Replenishing of the water table (usually by rain or melting snow)
Runoff
 Water that does not get absorbed by the ground and flows over an impermeable surface
 Usage
 When plants &/or animals remove water from the water table (ground water storage)
 Surplus
 Occurs when the water table is full and usage is low (may cause floods)
 Defecit
 Occurs when usage is high & the water table drops (drought)
1. Effects of Human Activities on Water Cycle
Humans alter the water cycle by:
 __________________________________ large amounts of freshwater

Clearing ______________________________________________________________________

____________________________________________________ surface and underground water

____________________________________________ to climate change
2. Carbon Cycle/Global Warming Affect the Water Cycle
Increased ____________  increased ↑ ________________________________, runoff, and soil moisture
Feedback from increased temp:
Increased cloud cover  (1) reflects light back into the atmosphere, so decreased temp (upper atmosphere)
Increased cloud cover  (2) water vapor absorbs heat in the atmosphere, so increased temp (below clouds)
B. Carbon Cycle
A biochemical circulation of the element carbon through
the Earth System

1. Carbon is the
_____________________________________

_____________________________________

2. Carbon is changed into different compounds as it goes through the cycle




CH4 = _______________________________________________
CO2 = _______________________________________________
C6H12O6 = ___________________________________________________
3. ________________________enters atmosphere as Carbon Dioxide (CO2):

______________________________________________________ (Respiration)
 O2+Food = CO2+H2O+Energy

Produced by ________________________________

Released by _______________________________________________________________

Released by ______________________________________

_________________________________________________________________________
4. ______________________________________________ as CO2 taken up by plants during
photosynthesis (trees, grass, algae)


CO2+H2O+sunlight =C6H12O6(Food) +O2
Carbon is stored in plant tissue as
(C6H12O6) Carbohydrates
Ex. ______________________
5. Animals eat plant ___________________________
6. Or __________________________________________________________ in oceans dies

Settles to bottom & becomes ________________________________

Lithification- _______________________________________________________________
7. Ocean is known as a Carbon Sink because it
_____________________________________________
8. Carbon dioxide from Atmosphere is dissolved in the ocean during ___________________________
 Forms bicarbonate & Calcium Carbonate (lime that forms __________________________)
Carbon Cycle
Name __________________________________
Date _____________________ Per ___
Air
Land
Ocean
1. Burial – Limestone Formation
2. Fossilization
Use the following terms to fill in the blanks & arrows above: Shell formation, photosynthesis (use twice), respiration (use
twice), oil, coal, Natural gas, limestone, absorption & desorption, weathering & erosion, burning & decay, volcanism,
lithification.
Copyrighted, 1998 - 2004 by Nick Strobel www.astronomynotes.com.
9. Effects of Human Activities on Carbon Cycle
Adding excess CO2 to the atmosphere:
 _________________________________________

________________________________ faster than
it is replaced.
10. Relevance of Carbon Cycle to Climate Change

CO2 in atmosphere is increasing 0.4% a year
(= _____________ in 100 yr.)

Increasing CO2 causes increased temperatures. (________________________________)

Heat captured by the atmosphere:
a.
CO2 = ____________
b.
CH4 = ____________
c.
CFCs = ___________
d.
NO2, H2O, O3 = 15%
C. Nitrogen Cycle
 Nitrogen
 Important to living things because it is required to form __________________________
 _________________________________________________

Most living things cannot use __________________ gas in their cells.
1. Nitrogen fixing bacteria
Use nitrogen from the atmosphere to form ____________________________________________
 Form of nitrogen that _____________________________
Live in the ____________and in _________________________________________
Ex of Legumes: _______________________________________________________________
2. Nitrifying bacteria make NH3 into:
 NO2- = ___________________________
 NO3- = ________________________
 Most common form of nitrogen for plants, _______________________________________
3. Animals get the nitrogen they need from _______________________________________ they consume
4. Decomposers return the nitrogen to the soil in the form of __________________which restarts the cycle
5. Human Alter the Nitrogen Cycle by:
Adding gases that contribute to _________________________________
Adding nitrous oxide to the atmosphere through farming practices which can warm the atmosphere and
deplete ozone (tilling soil too much)
__________________________________________ water from nitrate ions in inorganic fertilizers
Releasing nitrogen into the troposphere through ______________________________
6. Effects of Human Activities on the Nitrogen Cycle

Human activities such as production of fertilizers _____________________________________
than all natural sources combined
a. Effects of Increased Nitrogen

1. Loss of soil nutrients
(Ex. ____________________________________)
2. __________________________of rivers and
lakes (fertilizers and combustion of coal)
3. Increases nitrogen oxides in the atmosphere
i. (__________________________________—global warming)
ii. (__________________________________—increasing UV penetration).
4. Aids in spreading __________________ into nitrogen poor areas
(Eutrophication of lakes, ponds, streams)
Eutrophication - The process by which a body of water acquires a high concentration of nutrients.
Ex. of nutrients = ______________________________________

Promotes excessive growth of __________________

Algae die and __________________

High levels of organic matter and the decomposing organisms deplete the water of
available ____________________________

Causes the _______________ of other organisms, such as fish
5. Increasing nitrogen increases ____________________________ (linked to carbon cycle)
6. Increasing acidification increases ___________________ (increases rate of _________________ cycle)
D. Sulfur Cycle
1. Key Compounds of the Sulfur Cycle
a. Dimethyl sulfide
b. Sulfur dioxide
c. Sulfur trioxide
d. Sulfuric Acid
e. Ammonium Sulfate
f. Hydrogen Sulfide
a. Dimethyl sulfide ______________________
•
Emissions from ___________________________
•
Occurs over ______________________________
b. Sulfur dioxide SO2
 Emissions:
 Industries example : ________________________
 Volcanoes
c. Sulfur trioxide ______________
• Primary agent in acid rain
•
SO3 (l) + H2O (l) → H2SO4 (l)
d. Sulfuric acid _____________________

Gas released by cutting ________________ combines with ____________ in your eye to
form ________________________

Principal uses include:



Ore processing
________________________________
Oil refining
e. Ammonium Sulfate __________________


Made when ___________________ reacts with ____________________
Uses:

Fertilizer

Agricultural spray
- aids for water soluble pesticides
f. Hydrogen Sulfide __________________

Emitted by _________________ and __________________

Remains in atmosphere for ________________

Changes into sulfur dioxide
1. Importance in Biochemical Cycle
 __________________________________________________________________

Bacteria oxidize ______________________________________ (black smokers of ocean floor)

Factor for plant ________________________
2. Effects of Human Activities on the Sulfur Cycle

Humans add sulfur dioxide to the atmosphere by:

Burning ______________________________

Refining _____________________________________________________________

Convert sulfur-containing metallic ores into free metals such as copper, lead, and zinc releasing sulfur
dioxide into the environment.
E. Phosphorous
1. First isolated in 1669 by Hennig Brand, (German physician and _____________________)

Trying to make __________________

Let urine stand for days

Boiled it down, captured gases & condensed them

Results = white, waxy substance that glowed in the dark

Brand had discovered phosphorus
2. Greek means ______________________________
3. Essential to living organisms because it forms
•
________________
•
RNA
•
________________
•
_______________________________________________
4. Not common in _____________________________
5. Slowest ____________________________________ cycle
6. Remains mostly on land in _____________________________ &
in ____________________________________________
7. Strictly a Lithosphere – Hydrosphere – Biosphere cycle (__________________________________)
8. Effects of Human Activities on the Phosphorous Cycle

Removal large amounts of phosphate from the earth to make ______________________

Reduce phosphorous in tropical soils by ______________________________________

Add excess phosphates to aquatic systems from runoff of animal wastes and fertilizers
II. Laws of Thermodynamics
 1st Law –energy/matter cannot be ___________________________________________, only changed
from one form to another

____________________________________________________________________________

2nd Law- when energy changes, it is converted from a more useful, more _______________________
form to a less useful, less concentrated form.

Energy can never be recycled completely. Some energy is lost, usually as _______________________
III. Intro Energy Cycle
 The movement of energy into & out of the Earth System
 The amount of energy that enters the system should = the amount of energy that is removed
 __________________________

__________________________

__________________________
A. Solar Power

99.985% of energy that enters the Earth’s system is from the sun

_________________________________________________________________________________

Causes rocks to weather, forming ______________________
1. Albedo
o The percentage of ______________________________________________ off the Earth without
being changed

Forest = ________________________________ reflects 5-10%

Snow covered field = ________________________ 80-90%
B. Geothermal Energy
 .013% is energy from within the Earth


_________________________________________________
____________________________________________________
____________________________________________________

Powers ______________________________________________
____________________________________________________
C. 3. Tidal Energy
 .002% is energy that results from the Sun & Moon’s pull on Earth’ s ocean

_____________________________________________