Unit A
Systems

Objects or groups of objects that has a
relationship to something else
 Open
 Energy and matter cross the systems boundaries
 humans, trees
 Closed
 Allows energy but not matter to cross boundary
 Earth, Biosphere
 Isolated
 Allows neither energy or matter to flow across
boundary
 Universe
BIOSPHERE




Radiant energy from sun interacts with
a thin layer of air, land and water on or
near the earth’s surface
All life on earth exists here
Living (biotic) and non living (abiotic)
components
Closed system
No real
boundaries,
everything
on Earth is
connected.
 Do not see
countless
interactions
or the
impacts of
human
activity

Biosphere

3 zones
1.Lithosphere (land)
2.Hydrosphere (water)
3.Atmosphere (air)
 continuously interact and these interactions change
daily
Biosphere
Part A: Make a chart that compares and
contrasts the three components of the
biosphere
Part B: Briefly explain how each part of the
biosphere supports life
Levels of Biosphere
Biosphere
Made up of
Ecosystems
Made up of all the abiotic
and biotic elements of one
specific area
Made up of
Communities
All biotic elements in a
specific ecosystem
Made up of
Populations
Groups of similar species
in a specific community
Made up of
Organisms
A single being within a
specific population
Matter Cycling in the Biosphere

organisms depends on matter already
available on earth (closed system)
 It is possible that a carbon atom that helped make up a T
Rex 70 million years ago can be somewhere in your body

New matter is not introduced so nutrients
are cycled and recycled between the
environment and organisms
 These cycles are called the BIOGEOCHEMICAL
CYCLES
Matter


Matter is mostly made up of the
following elements and there is a
specific cycle for each:




Carbon
Hydrogen
Oxygen
Nitrogen




Carbohydrates (energy for cells)
Lipids (storage in cells)
Proteins (structure in cells)
Nucleic Acids (genetic material in cells)
These four elements make up all basic
compounds used by living organisms
Biogeochemical Cycles
Cycling of matter through biotic and
abiotic parts of ecosystems allows
organisms to obtain essential nutrients
 O, C, N, travel easily in both water & air
 P does NOT travel in air but in soil and
water
 Similar and interrelated

 Disruptions in one can affect another
Nutrient Reservoirs

At each step in every cycle, substances
are temporarily stored in nutrient
reservoirs (organisms, soil, air, water)or
move from reservoir to reservoir
 E.g. Carbon cycles from producer to consumer to
decomposers and back to atmosphere rapidly
 Fossil fuels is stored carbon that is unavailable to
organisms for millions of years
The Cycling of Matter in the
Biosphere
Hydrological Cycle

Water
 absorbs and release thermal energy and moderates
temperature fluctuations
 Medium in which metabolic reactions take place
 Is an excellent solvent
 Makes up over 60% of the cell’s mass
 Product and reactant of photosynthesis and cellular
respiration
 Abiotic (air, water, land) and biotic organisms
Carbon/Oxygen Cycle

Carbon
 Key element for living things
 Cellular respiration/photosynthesis
 Biotic and abiotic (air, land, water)

Rapid Cycling
 Plants animals and decomposers play important role
 Forest fires

Slow Cycling
 3 main reservoirs of carbon in the atmosphere,
oceans, earth’s crust
 Weathering
Carbon Cycle
Phosphorus Cycle

Phosphates

Short Term Cycle

Long Term Cycle
 Key elements in making ATP and calcium in bones
 Animals obtain phosphorus by consuming foods
such as milk, grain and meat
 Producers such as plants and algae can only use it
in forms of phosphates which dissolve in water
 NOT IN AIR
 living organisms
 Rocks in Earth’s crust
Phosphorus Cycle
Nitrogen Cycle

Nitrogen

Nitrogen Fixation

Ammonification

Denitrification
 Makes up 78.1% of atmosphere
 Essential part of proteins and DNA
 Abiotic (Air, water, land) and biotic
 Process to convert atmospheric nitrogen into useable
ammonium by bacteria or lightning
 Process of converting ammonium into nitrite then
useable nitrate by bacteria so plant can use it
 Process of converting nitrite and nitrate back into
nitrogen gas
Human Impact on Cycles
Carbon-deforestation, burning fossil fuels
add carbon to reservoir
 Nitrogen and Phosphorus- Fertilizer add
phosphates and nitrates to the soil
 Water-burning fossil fuels adds sulfuric
acid and nitric acid to the water cycle
(acid rain)

ENERGY FLOWS AND
MATTER CYCLES
The need for energy
All organisms need energy to stay alive
Use energy to grow, maintain body
processes, reproduce and some to move
 Energy obtained from carbs and other
energy rich organic molecules


The fate of energy

Energy does not and cannot cycle as
matter does it follows a one way path
through the biosphere
 1st law of thermodynamics
 Energy cannot be created or destroyed, it can only be
converted from one form to another or transferred
from one object to another
 2nd law of thermodynamics
 No process of energy conversion is 100% efficient,
with each conversion there is less energy available to
do useful work

Therefore a constant supply of energy is
necessary to sustain life
Energy Flow in the Biosphere
Energy that enters ecosystem is passed
from organism to organism and is used up
or exits the system via heat
 Energy drives the biogeochemical cycles
 Source of earth’s energy is the sun
 3 outcomes for radiant energy from the
sun

Radiant Energy from Sun
1% generates
wind
30% reflected by clouds or
surface of earth
>0.02 % is used by plants to
create useable energy
40% heats atmosphere and
earth’s surface
25% heats and evaporates water
30% is reflected back into space
ALBEDO EFFECT
 Describes the amount of reflected energy
 Greater the ability of area to reflect sun the
higher albedo therefore the lower the energy
absorption (light coloured, thick cloud cover,
dusty or “bald” -80%)
 Lower the ability of area to reflect sun the
lower the albedo therefore the higher the
energy absorption (forest canopies and water 25%)
 Average is 30 %
19% absorbed by atmosphere
 Gases such as H2O vapor & CO2 in
atmosphere
 Will heat the atmosphere or radiate back
into space
51% reaches surface of Earth
 Absorbed by land and ocean, warms
surface
 Heat radiates upward and back into space
 Of the energy that reaches ground only
small fraction reaches organisms for
photosynthesis
 Amount varies depending on type of organisms and
intensity of light
 Fraction of light that reaches is small but about 150
billion tonnes to 200 billion tonnes of organic
(carbon) matter is produced each year and this is
the matter that supports most life on earth.
0.023% of suns energy is used by living organisms
PHOTOSYNTHESIS AND CELLULAR RESPIRATION
Two chemical processes that occur in
nature to help animals and plants turn
solar energy into useable energy
 Plants use PHOTOSYNTHESIS to convert
energy

6CO2 + 6H2O + energy --> 6O2 + C6H12O6

Animals use CELLULAR RESPIRATION
to release energy
6O2 + C6H12O6 --> 6H2O + 6CO2 + energy


Complementary processes
Balance of those O2 and CO2 in the
environment
0.023% of suns energy is used by living organisms
Tracing the path energy takes from the sun to
organisms living on earth
FOOD WEBS/CHAINS visually show us
the step by step or interlocking “feeding”
relationships between organisms
Putting organisms into classifications
helps to organize the way they gain
energy from the sun



Three main levels in basic food chains/webs
1. 1st Trophic Level = Producers = Autotrophs
2. 2nd Trophic Level = Primary Consumers =
Heterotrophs
3. 3rd Trophic Level = Secondary Consumers =
Heterotrophs
Energy and the food chain
Energy is neither created nor destroyed
therefore once it enters a system it
stays and is either used up or lost as
heat into the system
 As you move up the trophic levels the
amount of energy available goes down
 Only 10% of energy from each level is
passed on
 The number of organisms at each level
is directly controlled by the amount of
energy available to each level

ECOLOGICAL PYRAMIDS
(pg 28-32)


Visuals that help represent the energy
flow in a system
Three types of pyramids
1. Pyramid of Biomass
A measure of total dry mass of all living things in the
ecosystem
2. Pyramid of Energy
A measure of energy at each level
3. Pyramid of Numbers
A count of the number or organisms at each level
Human impact on Energy


Hunting and fishing
Monocultures
Flow of Matter and Transfer of Energy
are linked
Six cycles involve biotic and abiotic
environment
 When living organisms take on nutrients
those nutrients become part of the biotic
environment
 Transfer of energy from organism to
organism affect biogeochemical cycles

Balance of Matter and Energy

Earth is similar to organisms must
maintain conditions within certain limits to
ensure a state of balance (Dynamic
EQUILIBRIUM)

Gaia hypothesis-James Lovelock-
 Biosphere regulates itself, needs constant input of
energy and cycling of nutrients
Ecosystem Productivity
Rate at which an ecosystem’s producers
capture and store energy within organic
compounds over a certain length of time
 Rate of productivity depends on a number
of variables

 Biotic factors
 Number of organisms at each level especially
producers and decomposers
 Abiotic factors
 Temperature, amount of light and heat, rainfall,
nutrient availability
Ecosystem Productivity
This is measured in energy/area/year
(J/m2/a)
 We look at how much BIOMASS is created
by the organisms
 Look at the diagram!

Replicating Earth’s Biosphere

Scientist have tried to replicate the self
regulating conditions of the biosphere in
artificial environments
Biosphere 2
Large scale biosphere experiment
constructed closed systems
 Several months until the oxygen levels
dropped and carbon dioxide levels rose
 Proved that energy and matter exchange
is extremely complex
 Research facility showed that delicate
balance

http://www.b2science.org/who/fact
NASA: Advanced Life Support (ALS)
Research plants grown in space for
oxygen and food
 Conversion of waste into usable energy
 Self sustaining colonies for humans
 Devon Island (Canada) hypothetical
colony on Mars

http://www.nasa.gov/centers/ames/research/technology-onepagers/advanced-life-support.html