Biogeochemical Cycles
• Defined:
Movement of
water through
the Earth and its
atmosphere
• 75% of the
Earth is covered
in water
• Less than 1% is
drinkable.
• Most water is
salty or frozen
Water Cycle Pathway
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• Precipitation:
sleet,
or hail
falls
when
water
drops
Evaporation:
Water
vapor Rain,
starts
Heat snow,
changes
to cool…condensation
water
from
a liquid
occursto
a gas
heavy
Transpiration:
Water
evaporates
from the
leaves
of plants
• become
Condensation:
process
where water
vapor
turns
into a
• Runoff:
runs called
down hill
into rivers, lakes, streams, oceans…
throughWater
openings
stomata
liquid
• Infiltration: Water soaks into the soil and collects as groundwater
Oxygen Cycle
O2
O2
• Autotrophs: Release O2 into atmosphere by photosynthesis
• Most life needs O2 for cellular respiration
– Creates ATP (energy) for cells
CO2
CO2
CO2
CO2
CO2
Carbon
(C)
Cycle
CO
CO
2
CO2
CO2
2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
glucose
Carbon
glucose
glucoseCO2
glucoseglucose
glucose
• Human Contribution
• Decomposers
Plants
Animals
– Release excess CO2 into atmosphere when fossil fuels (coal, oil,
– Obtain
Absorb
Glucose
CO
passed
photosynthesis
up
feeding
the food
onchain
dead organisms
naturalglucose
gas)
areby
burned
for
energy
2 for
–
Release
CO
glucose
into
(C
in
atmosphere
their
) after photosynthesis
– Carbon
Cycle
is released
out
of
balance
2 exhaled
6H
12O6waste
Phosphorus (P) Cycle
P
P
P
P
P
• Phosphorus
Step 3:
needed to
Consumers
make ATP,
ingest
P
• Step
DNA,4:
lipids
• Decomposers
Problem: No
obtain
P
phosphorus
in
when
feed on
atmosphere
• the
Stepdead.
1:
• Step
5:
Phosphorus
Decomposers
released by
release
P of
weathering
within
rocks waste
into soil
• back
Step 2:
or
water
Producers
• Cycle
absorbrepeats
P
through their
roots
Phosphorus (P) Cycle
P
P
P
P
P
P
• Human
Contribution
– Adding
excess P from
fertilizers
– P washes into
lakes, etc…
– Excess P
causes
extreme
plant & algae
growth
Nitrogen (N) Cycle
N2
N
N
N
N
Usable N
Nitrogen
fixation
N
Usable N
• Nitrogen
Step 4: needed
Producers
to build nucleic
absorb
N
acids (DNA/RNA)
• through
Problem:their
roots
Nitrogen in
• Step
5:
atmosphere
(N2)
Consumers
is unusable
ingest N
• Step 1: Bacteria
through the
in soil convert N2
food chain
into usable
• Step 6:
forms
Decomposers
• Step
2: N
Bacteria
obtain
from
absorb
dead usable N
• organisms…
Step 3: Bacteria
return
soil
releaseNNto
waste
in
their
into
air waste
Nitrogen (N) Cycle
O2
ONO
O
N2
N
N
NO
O2
NON2
NO
NO
O2
N2
N
NO
O2
O
• How does lightning help?
– Energy breaks atmospheric nitrogen into Nitrogen oxide
– Nitrogen oxide falls in rain to soil
Review
1) Name and define the 6 stages of the water cycle.
2) How is oxygen released into the atmosphere?
3) In which cellular process is oxygen removed and used from the
atmosphere?
4) What are the 4 major types of organic molecules?
5) In which cellular process is carbon dioxide released into the
atmosphere?
6) How are humans disrupting the carbon cycle?
7) Which objects release phosphorus over time?
8) How are humans disrupting the phosphorus cycle?
9) Which organisms help convert gaseous nitrogen into a usable form
of nitrogen in the nitrogen cycle?
10) How do plants obtain nitrogen?
11) Of the major molecules that we have studied this year, which ones
contain nitrogen and/or phosphorous?