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