Upload
others
View
16
Download
0
Embed Size (px)
Citation preview
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
• Evaporation: Heat changes water from a liquid to a gas
• Transpiration: Water evaporates from the leaves of plants through openings called stomata
Water Cycle Pathway
..
...
... . .. ..
... .
.
.
.
.. .
..
. ...
.
Water Cycle Pathway
..
...
... . .. ..
... .
.
.
• Water vapor starts to cool…condensation occurs
• Condensation: process where water vapor turns into a
liquid
.
.. .
..
. ...
.
Water Cycle Pathway
..
...
... . .. ..
... .
.
.
• Precipitation: Rain, snow, sleet, or hail falls when water drops
become heavy
• Runoff: Water runs down hill into rivers, lakes, streams, oceans…
• Infiltration: Water soaks into the soil and collects as groundwater
.
.. .
..
. ...
.
Oxygen Cycle
• Autotrophs: Release O2 into atmosphere by photosynthesis
• Most life needs O2 for cellular respiration
– Creates ATP (energy) for cells
O2
O2
Carbon (C) Cycle
• Plants– Absorb CO2 for photosynthesis– Release glucose (C6H12O6) after photosynthesis
CO2
glucose
glucose
glucose
CO2
CO2
glucose
glucoseglucose
Carbon
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
CO2CO2
CO2
CO2
CO2
CO2
CO2CO2
Carbon (C) CycleCO2
glucose
• Animals– Glucose passed up the food chain– CO2 exhaled into atmosphere
glucose
glucose
CO2
CO2
glucose
glucoseglucose
Carbon
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
CO2CO2
CO2
CO2
CO2
CO2
CO2CO2
Carbon (C) CycleCO2
glucose
glucose
glucose
CO2
CO2
• Decomposers– Obtain glucose by feeding on dead organisms– Carbon released in their waste
glucose
glucoseglucose
Carbon
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
CO2CO2
CO2
CO2
CO2
CO2
CO2CO2
Carbon (C) CycleCO2
glucose
glucose
glucose
CO2
CO2
glucose
glucoseglucose
Carbon• Human Contribution
– Release excess CO2 into atmosphere when fossil fuels (coal, oil, natural gas) are burned for energy
– Cycle is out of balance
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
CO2CO2
CO2
CO2
CO2
CO2
CO2CO2
Phosphorus (P) Cycle • Phosphorus needed to make ATP, DNA, lipids
• Problem: No phosphorus in atmosphere
• Step 1: Phosphorus released by weathering of rocks
• Step 2: Producers absorb P through their roots
P
P
P
P
P
Phosphorus (P) Cycle
P
P
• Step 3: Consumers ingest P
• Step 4: Decomposers obtain P when feed on the dead.
• Step 5: Decomposers release P within waste back into soil or water
• Cycle repeats
P
P
P
Phosphorus (P) Cycle
• Human Contribution– Adding
excess P from fertilizers
– P washes into lakes, etc…
– Excess P causes extreme plant & algae growth
PP
P P
PP
Nitrogen (N) Cycle • Nitrogen needed to build nucleic acids (DNA/RNA)
• Problem: Nitrogen in atmosphere (N2) is unusable
• Step 1: Bacteria in soil convert N2
into usable forms
• Step 2: Bacteria absorb usable N
• Step 3: Bacteria release N waste into air
N2
Usable N
N
N
N
Usable N
N
Nitrogen fixation
N
Nitrogen (N) Cycle • Step 4:
Producers
absorb N
through their
roots
• Step 5:
Consumers
ingest N
through the
food chain
• Step 6:
Decomposers
obtain N from
dead
organisms…
return N to soil
in their waste
N2
Usable N
N
N
N
Usable N
N
Nitrogen fixation
N
Nitrogen (N) Cycle
• How does lightning help?
– Energy breaks atmospheric nitrogen into Nitrogen oxide
– Nitrogen oxide falls in rain to soil
N2
N2
N2
O2
O2
O2
O2
NN
OO
NNOO
NN
OO
OO
NO
NO
NO
NO
NO
NO
Review1) 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?