1. Nutrient Cycles aka Biogeochemical Cycles
matter that organisms must have to survive

2. 1. Water Cycle
involves: evaporation, condensation, precipitation, infiltration, runoff, percolation, and transpiration
* absolute humidity  actual amt of water vapor in the air
* relative humidity  absolute humidity ÷ by the amt of water vapor the air can hold at that temp. X 100 = %
high temps = more H2O vapor the air can hold

3. * precipitation will only occur if water vapor has condensed around tiny particles called . . .
CONDENSATION NUCLEI
can be volcanic ash, dust, smoke, sea salts, particulates from factories & cars
How do humans affect the water cycle?

5. Carbon is a Girl's Best Friend

6. 2. Carbon Cycle a. b. Respiration
- primary component of all organic compounds
(carbs, fats, proteins,DNA)
- based on CO2
- includes 2 biological processes a.
b. Respiration
glucose
oxygen
carbon dioxide
water
mitochondria

7. Areas on Earth where large amounts of a nutrient is stored are known as SINKS or RESERVOIRS
A major sink for carbon is the oceans.
- CO2 is dissolved in the water.
- Much carbon is also found
in the form of CaCO3 to
build shells and skeletons
of sea organisms

9. How do humans affect the carbon cycle?

10. 3. Nitrogen Cycle N2 makes up 78% of our air!
All organisms must have nitrogen as it is an essential component of DNA, RNA, and proteins—the building blocks of life.
The largest single source of nitrogen on Earth is in the atmosphere.
N2 makes up 78% of our air!

11. In one of nature’s great ironies…
The majority of the air we breathe is N2, however most living organisms are unable to use nitrogen in that form!

12. How does N2 get changed into a form that can be used by most living organisms?

13. (1) Nitrogen Fixation (4) Denitrification (3) Nitrification
Nitrogen Cycle
(3) Nitrification
(2) Ammonification

14. There are two types of “Nitrogen Fixing Bacteria”
* Nitrogen fixation  conversion of N2 to
NH3
There are two types of “Nitrogen Fixing Bacteria”
Symbiotic Bacteria
(“fixes” 70% of N2)
Symbiotic bacteria live in nodules on the roots of legume plants (peas, soybeans, alfalfa) and provide the plants with ammonia (NH3) in exchange for the plant’s carbon and a protected home.
Free Living Bacteria

15. * Ammonification conversion of amino acids
from decaying organisms to NH4+
Bacteria converts organic nitrogen to ammonium
Ammonium (NH4+) can be used directly by some plants
Ammonium (NH4+) may also be stored in the soil

16. * Nitrification conversion of NH3 to NO2-
and NO3- (occurs in bacteria)
Nitrifying bacteria in soil combine ammonia with oxygen
Ammonia changes to nitrites
Nitrifying bacteria in soil convert nitrites to nitrates
Ammonia
Nitrites
Nitrates
Plants absorb nitrates
(NH3)
(NO2-)
(NO3-)

17. Nitrogen in atmosphere closes the nitrogen cycle!
* Denitrification conversion of forms of
nitrogen back to N2 by
bacteria
Nitrogen in atmosphere closes the nitrogen cycle!
Nitrates in soil
(NO3-)

19. Other ways that nitrogen returns to the atmosphere…
Emissions from industrial combustion and gasoline engines create nitrous oxides gas (N2O).
Volcano eruptions emit nitrous oxides gas (N2O).
How do humans affect the nitrogen cycle?

21. 4. Phosphorus Cycle - Found mostly in proteins, lipids and
nucleic acids.
- Circulates
through
water,
organisms
and rock
- Very little
found in the
atmosphere

22. - major limiting factor in plant growth so
it is a main ingredient in fertilizer

24. 5. Sulfur Cycle - In organisms, found mostly in proteins
- Most of Earth’s sulfur is stored as SO4-2
underground in rocks and minerals in
addition to ocean sediments.

25. How do humans affect the sulfur cycle?