Biological Cycles
Overview
• Matter
• Biogeochemical Cycles
C.H.O.N.P. <- Elements living organisms are made of
Matter
• All material in the universe that
has mass and occupies space is
called matter.
• Atoms- smallest unit of an
element
Carbon, Hydrogen, Oxygen,
Nitrogen, Phosphorus
• Matter is neither created or
destroyed
• Matter cycles through our world
• And Nutrients are matter that
organisms need for life. These
also circulate throughout the
environment in
biogeochemical cycles.
Biogeochemical Cycles
• BIO – refer to the LIVING
organisms
• GEO – refers to the Earth, rock
and LAND.
• CHEMICAL – molecules,
REACTIONS and atoms.
Water Cycle
Defined: Movement of water
through the atmosphere
• 75% of the earth’s surface is
covered by water
—Most water undrinkable (salty
& frozen)
Water Cycle
• Water rises in two ways:
1) Evaporation: heat from the sun
changes water from liquid to gas
2) Transpiration: evaporation of water
from the leaves of plants
H2O
H2O
Water Cycle
• Water rises in two ways:
H
O
H
1) Evaporation: heat from the sun
changes water from liquid to gas
2) Transpiration: evaporation of water
from the leaves of plants
— Stomata: microscopic pores on underside
of leaves
H2O
H2O
H2O
H2O
H2O
Water Cycle
H2O
H2O
H2O
H2O
H2O
H2O
H2O
• Water rises in two ways:
1) Evaporation: heat from the sun
changes water from liquid to gas
2) Transpiration: evaporation of water
from the leaves of plants
— Stomata: microscopic pores on underside
of leaves
H2O
H2O
H2O
H2O
H2O
H2O
H2O
H2O
Water Cycle
H2O
H2O
H2O
H2O
H2O
H2O
• Condensation: changing of water
vapor to liquid water
— Cause: cool temperatures
Moisture in
the air
condensed
when it came
into contact
with the cold
bottle
H2O
H2O
H2O
H2O
H2O
H2O
Water Cycle
H2O
H2O
H2O
H2O
H2O
H2O
• Condensation: changing of water
vapor to liquid water
— Cause: cool temperatures
— Clouds are the effects of
condensation
H2O
H2O
Water Cycle
H2O
• Precipitation: Falling of water back to the
surface of the Earth
— Rain
— Snow
— Sleet
— Hail
H2O
H2O
Water Cycle
H2O
• On the ground:
1) Runoff: water runs downhill into
rivers, lakes, oceans…
2) Infiltration: water soaks into soil and
collects as groundwater
HH
2O
2O
H2OH2OHHO2O
Water Cycle
• On the ground:
1) Runoff: water runs downhill into
rivers, lakes, oceans…
2) Infiltration: water soaks into soil and
collects as groundwater
well
Groundwater is
“recharged” by
infiltration
condensation
precipitation
Water Cycle
transpiration
infiltration
runoff
evaporation
Carbon Cycle
• Carbon (C) is the basis of organic
molecules
– Proteins
– Carbohydrates
– Lipids
– Nucleic acids
CO2
CO2
Carbon Cycle
CO2
CO2
• Plants and Producers
– Absorb CO2 during photosynthesis
– Produce glucose (C6H12O6) via photosynthesis
glucose
CO2
CO2
Carbon Cycle
CO2
CO2
• Animals
– Glucose moves up the food chain when animals eat plants
– CO2 released into atmosphere
CO2
CO2
glucose
glucose
CO2
CO2
Carbon Cycle
CO2
CO2
• Decomposers
– Obtain glucose by feeding on the dead
– CO2 released into atmosphere
CO2
CO2
CO2
glucose
glucose
glucose
glucose
glucose
CO2
CO2
Carbon Cycle
CO2
CO2
• Human contribution
– Excess CO2 is being released from the burning of fossil fuels
(coal, oil, natural gas)
– Cycle is out of balance
CO
CO
CO
CO
2 22
2
CO
22 2
CO
CO2
CO2
CO2
glucose
glucose
glucose
glucose
glucose
CO2
CO2
Carbon Cycle
CO2
CO2
CO
CO
CO
CO
2 22
2
CO
22 2
CO
CO2
CO2
CO2
glucose
glucose
glucose
glucose
glucose
Nitrogen Cycle
N
N
• Problem:
Nitrogen in
atmosphere (N2)
is unusable
– N2 bonds very
stable
• Nitrogen
needed to build
DNA
Nitrogen Cycle
• Step 1: Soil Bacteria & Bacteria in Legume roots convert N2 into
usable nitrates
N2
• Step 2: Bacteria absorb nitrates… release N waste into air
• Step 3: Producers absorb nitrates through their roots
• Step 4: Consumers ingest N through the food chain
• Step 5: Decomposers obtain N from the dead… return
nitrates to soil
N
N
N2
N
Nitrates
Nitrogen fixation to Ammonium
Nitrates
Nitrates
Nitrates
Nitrates
O O
NO NN O
O
N
N
The Role
of LightningO
O
O
N
OO NN O
N
N
O
N
O
O N
O
O
O
O
N
N
O
O N
N
O
OO
N
O
O
N ON N
O N O
O
N N
O
O N O
O
O
O
N N
O N O
O
N N
O
O
O N
N O
O
O O
• Energy from lightning breaks apart N2 into N… and O2 into O
Phosphorus Cycle
• Unlike the other cycles, phosphorus cannot be found
in air in the gaseous state.
• The phosphorus cycle is the SLOWEST cycle.
• Phosphorus is most commonly found in rock
formations and ocean sediments as phosphate salts.
• Phosphate salts that are released from rocks through
weathering usually dissolve in soil water and will be
absorbed by plants.
Quickly complete your Cycle
Diagrams
Phosphorus Cycle
• Animals absorb phosphates by eating plants or planteating animals.
• When animals and plants die, phosphates will return to
the soils or oceans again during decomposition.
• After that, phosphorus will end up in sediments or rock
formations again, remaining there for millions of years.
• Eventually, phosphorus is released again through
weathering and the cycle starts over.
Human Impacts
richness
of nutrients
in a
on theexcessive
Nitrogen
and
Phosphorus
Cycle
body of water, frequently due to runoff
from the land, which causes a dense
growth of plant life and death of animal
life from lack of oxygen.
• Increased use of fertilizers increases
phosphorus and nitrogen runoff into our
waterways and contributes to eutrophication.