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Biogeochemical Cycles
24/103 required by organisms
Macronutrients: C,H,N,O,P,S
Micronutrients
BIOGEOCHEMICAL CYCLES
The complete pathway that a chemical element takes through the biosphere, hydrosphere, atmosphere and lithosphere.
Elements transferred between compartments (pools)
Active: accessible to living things
Storage: inaccessible
CARBON CYCLE
atmosphere
biosphere
res
pir
ati
on
ph
oto
sy
nth
es
is
CARBON CYCLE
CARBON CYCLE
atmosphere
biosphere
res
pir
ati
on
ph
oto
sy
nth
es
isco
mb
ust
ion
A
A
AA
A
S
S
S
S
Carbon Cycle Simulation
Enter the carbon cycle…….
You are a carbon atom.
You are now in a molecule of CO2 in the atmosphere.
Flip 2 coins:
Your carbon atom returns or remains in the atmosphere .
Flip 2 coins:
Flip 2 coins:
Your carbon atom is absorbed into a plant leaf.
SUNLIGHT!PHOTOSYNTHESIS!Your carbon atom is incorporated into a sugarmolecule by photosynthesis.
C6H12O6
Your carbon atom is now in a molecule of sugar in a plant.
Flip 2 coins:
C6H12O6
Flip 2 coins:
Your carbon atom is now in a protein moleculeIn the plant tissue.
Flip 2 coins:
Your carbon atom in theplant tissue is eaten by aPrimary Consumer (anherbivore).
Your carbon atom is now in a molecule of dead organic matter (detritus)
Flip 2 coins:
Your carbon atom is now being burned (oxidized) in a fire. Your atom is being released to the atmosphere in a molecule of carbon dioxide.
The plant tissue with your carbon atom is now being ingested by a human.
Flip 2 coins:
The molecule containing your carbon atom is now being ingested by a primary detritus feeder (decomposer).
Flip 2 coins:
Your carbon atom is now in a molecule making up a tissue of your or another human’s body.
Flip 1 coins:
Your carbon atom is now in a molecule making up tissue of a carnivore.
Flip 2 coins:
The molecule containing your carbon atom is now being broken down in cell respiration to provide energy for the consumer. Your carbon atom is released as carbon dioxide.
The molecule containing your carbon atom is being ingested by a secondary consumer.
Flip 2 coins:
The molecule with your carbon atom is now being absorbed by a bacteria.
Flip 1 coin:
Your carbon atom is now being absorbed by a fungus.
Flip 2 coins:
Your carbon atom is now being ingested by an insect.
Flip 2 coins:
NO SUNLIGHT!
NO PHOTOSYNTHESIS!
The carbon atom returns to the atmosphere.
The sugar molecule is oxidized in cell respiration to provide energy for plant growth. Your carbon atom is released back to the atmosphere as carbon dioxide.
The plant tissue is eaten by an animal.
What kind of animal?
Flip 2 coins:
The plant dies.
The molecule containing your carbon is metabolized and into a molecule making up the tissue of the consumer’s body.
Flip 2 coins:
The molecule is not digested. It passes through the intestinal tract as waste.
Flip 2 coins:
The human dies and body is cremated.
The animal dies.
Flip 2 coins:
The animal is eaten by a third order consumer.
Flip 2 coins:
Flip 2 coins:
Nitrogen Cycle
78% of atmosphere is N2
not in a form usable by most organisms
Nitrogen fixation: conversion of nitrogen to usable form
Nitrogen Cycle
atmosphere
biosphere
loss
fixat
ion
gain
deni
trifi
catio
n
Nitrogen fixation
1. Biologicala) by soil bacteriab) by blue-green algaec) by legumes
2. Industriala) by manufacture of N fertilizerb) combustion of fossil fuels
Biological fixation
a & b) Free-living N-fixing bacteria and algae
-autotrophic
-fix nitrogen
c) Bacteria that are symbiotic
with legumes; infect
root nodules
Industrial fixation
a) Haber Process: manufacture of N fertilizer
b) Combustion of fossil fuels; forest fires
Denitrification
Denitrifying bacteria convert usable N back to N2 in atmosphere.
Outgassing
Release of N to atmosphere during volcanic eruptions.
Nitrogen fixation exceeds denitrification :
• N fertilizer
• Combustion of fossil fuels
• Cultivation of legumes
-excess nitrogen in biosphere
Nitrogen Cycle
atmosphere
biosphere
loss
fixat
ion
gain
deni
trifi
catio
n
