Download Matter Energy and Life

Chapter 3
Matter, Energy
& Life
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Outline
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Elements of Life
Organic Compounds and Cells
Energy
 Laws of Thermodynamics
 Photosynthesis/Respiration
Ecosystems
 Food Chains
 Ecological Pyramids
 Material Cycles
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Elements of Life
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MATTER - everything that has mass and
takes up space
 Solid - Liquid - Gas = 3 states of matter
CONSERVATION OF MATTER: The idea
that matter cannot be created nor destroyed
but is simply transformed from one form to
another
The atoms in your body may have been in a
dinosaur or a tree!
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Elements
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ELEMENTS - substances that cannot be
broken down into simpler forms by ordinary
chemical reactions
All matter consists of elements.
118 elements, but just four (oxygen, carbon,
hydrogen and nitrogen) make up 96% of the
mass of living organisms.
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Elements of Life
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All elements are composed of atoms.
ATOMS - smallest particles exhibiting
characteristics of the element
Atoms are composed of:
 PROTONS (positively charged +)
 NEUTRONS (neutrally charged)
 ELECTRONS (negatively charged -)
 Protons &neutrons are in the nucleus
 Electrons orbit the nucleus.
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Elements of Life
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ATOMIC NUMBER: Number of protons
ATOMIC MASS: Number of protons and
neutrons in an atom. Average of all isotope
masses
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Elements of Life
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ISOTOPE - forms of an
element differing in
atomic mass due to the
fact that isotopes have
different numbers
of neutrons
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Radioactive Isotopes
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Unstable isotopes
release energy and/or
particles: Alpha, Beta
or Gamma rays
Decay ends as a stable
form or another element
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Molecules & Compounds
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MOLECULE:
two or more
atoms joined
together
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COMPOUND:
a substance
composed of
2 or more
different kinds
of atoms
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Ionic Chemical Bonds
 CHEMICAL BOND - chemical energy
holding atoms together to form molecules
 IONIC BOND - Atoms with opposite
charges (ions) form a bond. One atom
loses one or more electrons, the other
atom gains one or more electrons
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Ionic Chemical Bonds
IONS - atoms that contain more or fewer electrons
than protons and therefore have a positive or
negative charge
ANIONS (-) have a negative charge.
CATIONS (+) have a positive charge.
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Covalent Chemical Bonds
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COVALENT - atoms share electrons
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WATER IS DIFFERENT!
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COVALENT BONDS IN WATER
In water the oxygen attracts the electrons more
strongly than the hydrogen atoms do, so the
hydrogen atoms have a slight positive charge and
the oxygen has a slight negative charge.
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WATER IS DIFFERENT!
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Water molecules are attracted
to each other due to the Polar
Covalent bonds of other water
molecules
“Universal Solvent” due to its
polar nature, water is capable
of dissolving most molecules
Cohesion – the attraction between water molecules
Surface Tension – the resistance of surface
molecules to be broken
Adhesion - water molecules
bonding to another surface
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WATER IS DIFFERENT!
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High Heat of Vaporization - requires a lot of energy
to turn liquid water into a vapor/gas
High Specific Heat – water must absorb a lot of
heat energy for the temperature to rise & it holds
onto this heat energy for a long period of time
Water EXPANDS when it freezes – this makes ice
less dense than liquid water allowing it to float
Water has a pH of 7 – it is NEUTRAL – in solution
the molecules break apart into (OH-) Hydroxyl Ions
and (H+) Hydrogen Ions
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Oxidation and Reduction
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OXIDATION - When an atom gives up one or more
electrons, it is “oxidized”.
REDUCTION - When an atom gains one or more
electrons, it is “reduced”.
Oxidation and reduction are important parts of how
organisms gain energy from food.
Endothermic: breaking bonds absorbs energy
_________________________________________
Exothermic: forming bonds releases energy
_________________________________________
Activation Energy: the energy needed to initiate a
chemical reaction (ie: friction to light a match)
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Acids, and Bases
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ACID – a substance that releases hydrogen ions
when put into water.
 Acids are Hydrogen (H+) “donors”
ie: sulfuric, hydrochloric, acetic, carbonic
BASE – a substance that releases hydroxide ions
(OH-) in water
 Bases easily bond with hydrogen ions producing
water and a neutral pH
ie: sodium hydroxide, calcium hydroxide
ammonium hydroxide,
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pH Scale
pH scale:
is logarithmic;
each step is 10X
0 to 6.9 is acidic
7 is neutral
7.1 to 14 is basic
ie: a substance with a
pH of 4 is ________x
More acidic than a
substance with a pH of 6
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ENVIRONMENTAL BUFFERS
BUFFER:
 a substance that accepts or releases
hydrogen ions
 buffers help to neutralize a solution
ie: adding lime (calcium carbonate) to a lawn will
decrease effects of acid rain
ie: a lake affected by acid rain may be buffered
by surrounding soils or alkaline bedrock of
limestone or igneous type rocks.
(Granite & shale are acidic and would be
detrimental to a lake affected by acid rain.)
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Organic Compounds
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Organic Compounds - Material making up
biomolecules, which in turn make up living things.
All organic compounds contain carbon.
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Four major categories of organic compounds:
- _________________
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_________________
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LIPIDS - CHO
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Lipids
 Fatty acids, oils, steroids, waxes, some hormones
 store energy
 produce cell membrane
 do not easily dissolve in water (non-polar)
 Hydrocarbon family (petroleum, methane)
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CARBOHYDRATES - CHO
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Carbohydrates
 Monosaccharides: simple sugars (glucose,
sucrose, lactose)
 Polysaccharides: starch & cellulose
 Store energy
 Used in cellular structure
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PROTEINS – CHON (S)
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Proteins
- Composed of chains of amino acids
 20 types of amino acids
- Folded into 3D shapes & perform countless
functions in cells and organisms
 antibodies, enzymes, cell shape,
hormones, transport other substances,
muscle contractions, etc.
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NUCLEOTIDES / NUCLEIC ACIDS - CHONP
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Nucleotides are monomers that combine to
create nucleic acids
- Made of a sugar, a phosphate group and
a nitrogen containing base
- Form long chains of RNA and DNA
- 4 types of DNA Nucleotides
adenine
guanine
cytosine
thymine (uracil in RNA)
- DNA extraction is very useful in taxonomy,
agriculture (GMO’s), medical genetics, etc.
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ORGANISM FUNCTIONING
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Cells - minute parts of a living organism which
carry out processes of life
 Surrounded by lipid & protein membrane
controlling flow of materials in and out of the cell
 Cells are composed of organelles that perform
cell functions.
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Prokaryotes – bacteria
Archea – single-celled extremophiles
Eukaryotes – protists, fungi, plants animals
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ORGANISM FUNCTIONING
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Enzymes - Molecular catalysts that
regulate chemical reactions.
Enzymes are usually proteins.
Metabolism – the total of all
enzymatic reactions performed by
an organism
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ENERGY
ENERGY – the ability to do work
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KINETIC - energy in moving objects
POTENTIAL - stored energy
CHEMICAL – potential energy stored in
food or fossil fuels
 NUCLEAR – nuclear atomic particles give way
to radioactive decay
 GRAVITATIONAL – due to height. Becomes
kinetic energy when the object falls
 MAGNETIC – forces between magnetic
materials (poles & distance)
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ENERGY
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MEASURING ENERGY
 Units of heat – Calorie - amount of energy
needed to heat 1 gram of H2O 1oC
 Units of work – Joule - work done to accelerate
1kg at one meter per second per second (m/s/s)
 1 calorie = 4.184 J
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ENERGY vs POWER
Energy is the ability to do work
Power is the rate at which work is done
Energy = power x time
Power = energy  time
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HEAT ENERGY
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HEAT - Energy that can be transferred between
objects of different temperature.
 When a substance absorbs heat, the motion of its
molecules increases and it may change state
(e.g. a solid to a liquid to a gas).
 When a substance releases heat, the motion of
its molecules decreases and it may change state
(e.g. a gas to a liquid to a solid).
 Remember.........
 Evaporation and condensation help distribute
heat around the globe. (Convection Currents)
 Heat storage in lakes & oceans moderates
climate and helps maintain different biomes
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USEFUL ENERGY
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Forms of energy that can be used for work is
considered useful and HIGH-QUALITY.
Diffuse forms of energy that can not be used
for work are considered LOW-QUALITY.
Which of the following have useful energy?
Atlantic Ocean
a flame
a piece of coal
a flowing stream
a warm brick
a rock rolling downhill
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HEAT - can be transferred between objects
by convection, conduction and radiation.
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THERMODYNAMICS: The study of Energy
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FIRST LAW OF THERMODYNAMICS -
a.k.a. Law of Conservation of Energy
Energy is neither created nor destroyed.
The amount of energy in the universe is
constant.
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SECOND LAW OF THERMODYNAMICS -
With each successive energy transfer, less
energy is available to perform work.
- ENTROPY (disorder) increases as energy
is used to do work.
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ENTROPY is a thermodynamic quantity
representing the amount of energy in a
system that is no longer available for doing
mechanical work.
As energy is used in doing work, some
energy is lost from the system.
 Lost as Heat, Friction, Sound, etc.
Video: https://www.youtube.com/watch?v=sAMlGyaUz4M
EXAMPLES:
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Energy for Life
Energy must be continually supplied by the
sun to keep biological processes running. As
energy flows through the various biological
processes, it becomes dissipated, diffuse,
unable to be used.
Ultimately, most organisms depend on the
sun for the energy needed to carry out life
processes.
 Exception: ____________________________
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Energy from the Sun
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Solar energy is essential for 2 reasons:
 Warmth - Most organisms can exist only in a
relatively narrow temperature range.
If too cold - ____________________________
If too hot - _____________________________
 Photosynthesis in plants
- Radiant energy is transformed into useful,
high-quality chemical energy in the bonds of
organic molecules. Almost all life on Earth
depends on photosynthesis.
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Energy From the Sun
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PHOTONS – Massless packets of electromagnetic
radiation that travel at the speed of light.
 Long wave energy (radio waves) are low energy
 Short wave energy (x-rays) are high energy
Of all insolation reaching the earth’s surface:
10% is ultraviolet
45% is visible light
45% is infrared
 Most energy is absorbed by the land &/or water,
or reflected back into space.
Only 1-2% of the sunlight falling on plants is
captured for photosynthesis.
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Electromagnetic Spectrum
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Photosynthesis
Occurs in chloroplasts within plant cells
6H20 + 6CO2 + solar = C6H12O6 + 6O2
energy
Water and carbon dioxide in the presence of
sunlight and chlorophyll (the green pigment
in chloroplasts) yield glucose and oxygen.
Glucose serves as primary fuel for all
metabolic processes. Energy in its chemical
bonds can be used to make other
biomolecules (lipids,proteins) or it can drive
movement, transport, etc.
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CHEMOSYNTHESIS
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Ancient organisms called ARCHAEA get
their energy from inorganic compounds such
as H2 and S found in vents in the sea floor or
from hot springs.
ARCHAEA represent one-third of all the
biomass on the planet.
Those living in ocean sediments create
enormous quantities of methane.
Fortunately, bacteria which consume
methane also exist.
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Cellular Respiration
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Photosynthesis captures energy, while
cellular respiration releases energy.
They are opposite processes!!
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C6H12O6 + 6O2 = 6H2O + 6CO2 + energy
(AEROBIC respiration provides more
energy than ANAEROBIC respiration)
 This is how animals get all their energy.
The reason that you need to breathe is to
supply this pathway with oxygen.
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Energy
Exchange in
Ecosystems
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From Species to Ecosystems
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Species - all organisms of the same kind that
are genetically similar enough to breed in
nature and produce live, fertile offspring
Population - all members of a species living
in a given area at the same time
Biological Community - all of the
populations of organisms living & interacting
in a particular area a.k.a. BIOTIC FACTORS
BIOMASS - the total mass of all living matter
in a specific area
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From Species to Ecosystems
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Ecosystem – a biological community and its
physical environment
 The physical environment includes ABIOTIC
(non-living) FACTORS such as climate, water,
minerals, soil, energy, etc.
 It is difficult to define the boundaries of an
ecosystem. Most ecosystems are open in that
they exchange materials and organisms with
other ecosystems.
BIOSPHERE – all ecosystems on earth. From
deepest ocean trench to highest mountain peaks.
(20 km thick layer around earth)
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ECOSYSTEM PRODUCTIVITY
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PRODUCTIVITY - the amount of biomass produced
in a given area in a given period of time.
PRIMARY PRODUCTIVITY – synthesis of organic
matter (biomass) by plants using solar energy
during photosynthesis.
SECONDARY PRODUCTIVITY - manufacture of
biomass by organisms that eat plants.
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ECOSYSTEM PRODUCTIVITY
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GROSS PRIMARY
PRODUCTIVITY (GPP)
measure of the total
amount of solar energy
captured by producers
during photosynthesis.
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NET PRIMARY
PRODUCTIVITY (NPP) measure of the total
energy captured
minus the energy
respired by producers.
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GPP VS NPP
NPP = GPP – Respiration
MEASURING GPP
Total CO2 taken up during photosynthesis =
CO2 taken up in light + CO2 produced in dark
This figure is expressed as
Kg C / m2 / day (year)
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CALCULATING NPP
A forest in N. America has a GPP of
2.5 kg C / m2 / year
This same forest loses 1.5 kg C / m2 / year
due to respiration.
Calculate the NPP in terms of % of GPP
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NPP for Ecosystems
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NPP is highest where temp is high, large
amounts of water and sunlight are present
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Identify 3 food chains in the picture below.
Each chain must have at least 3 organisms
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Food Chains and Food Webs
Food Chain – sequence of consumption from
producer to consumers
Food Web – multiple food chains, shows
complex relationships.
Trophic level - An organism’s feeding status in
a food web.
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TROPHIC LEVELS - Producers
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PRODUCERS – AUTOTROPHS
 All plants,
 Some protists – ALGAE
 Chemosynthetic Archaea
 Some bacteria
These organisms produce glucose through
photosynthesis or chemosynthesis and are
the base of the food chains.
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TROPHIC LEVELS - Consumers
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CONSUMERS – HETEROTROPHS
 All animals
 Some protists – PROTOZOA
 Herbivores eat only plants
____________________________
 Carnivores eat only animals - wolves
____________________________
 Omnivores eat both plants & animals
Bears, fox, raccoons
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TROPHIC LEVELS – Consumers
Some animals feed on dead organic matter
 SCAVENGERS eat carcasses
____________________________
 DETRITIVORES eat debris
(waste/decaying matter) breaking it down
into smaller pieces called DETRITUS
____________________________
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TROPHIC LEVELS - Decomposers
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DECOMPOSERS – SAPROTROPHS
- most BACTERIA
- All FUNGI – (mushrooms, mold)
Decomposers break down detritus into
elements and smaller molecules to be
recycled back into ecosystems through
matter cycles.
THIS IS AN EXTREMELY IMPORTANT ROLE
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PROCESS OF DECOMPOSITION
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Ecological Pyramids
Due to the Second Law of Thermodynamics,
energy is lost at each level of the pyramid.
 Energy is lost as heat during metabolism.
 Some energy is lost due to inefficient
predation.
10% Rule (Energy / Biomass)
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100 kg of clover yields
 10 kg of rabbit which yields
 1 kg of fox which yields
 0.01 kg of eagle
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Energy Pyramid
When organisms at various trophic levels are
arranged diagrammatically, they form a pyramid
with many more producers than consumers.
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Remember - 90% of energy is lost at each step
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INVERTED FOOD PYRAMIDS
INVERTED FOOD PYRAMIDS NEVER
REPRESENT ENERGY!!!
Inverted pyramids exist under a few conditions:
In this example, a single tree
can support hundreds or
thousands of insects which in
turn can support a few
carnivorous birds such as
woodpeckers.
Draw a fourth level
representing a hawk which
may prey on the woodpecker.
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INVERTED FOOD PYRAMIDS
Inverted pyramids exist under a few conditions:
In this example, a field of grass can support a few rabbits
which in turn support thousands of parasites – both internal
and external.
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INVERTED FOOD PYRAMIDS
Inverted pyramids exist under a few conditions:
Aquatic ecosystems are often inverted at the primary
consumer level. Phytoplankton reproduce quickly and have
short lives so there are never as many as the next level.
In contrast, grasses have longer lives and are rarely
consumed in their entirety. Thus, are a broader base for
terrestrial food pyramids.
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BIOGEOCHEMICAL CYCLES
Matter is conserved as it cycles over and over
through ecosystems.
1. HYDROLOGIC CYCLE
2.
3.
4.
5.
CARBON CYCLE
NITROGEN CYCLE
PHOSPHORUS CYCLE
SULFUR CYCLE
SOURCE – releases more of a compound than
it absorbs
SINK – stores more of a compound than it
releases
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Hydrologic Cycle
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HYDROLOGIC CYCLE
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Path of water through the environment
1. Solar energy evaporates water from surface
supplies and land.
2. Water is released by plants via TRANSPIRATION
3. Winds distributes water vapor around the globe.
4. Water vapor condenses over land surfaces,
producing precipitation.
5. Water runs off, percolates into sediment or is
taken up by plants
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Carbon Cycle
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Carbon Cycle
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Begins with intake of CO2 during photosynthesis.
Carbon atoms are incorporated into sugar which is
eventually released by cellular respiration either in
the plant or in organisms that consumed it.
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Sometimes the carbon is not recycled for a long
time. Coal and oil are the remains of organisms
that lived millions of years ago. The carbon in
these is released when we burn them. Some
carbon is also locked in calcium carbonate (shells,
limestone).
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Carbon Cycle
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The parts of the cycle that remove and store carbon
dioxide from the atmosphere (vegetation) are called
carbon sinks.
The parts of the cycle that release carbon dioxide
are called carbon sources.
Burning of fuels generates huge quantities of
carbon dioxide that cannot be taken up fast enough
by the carbon sinks. This excess carbon dioxide
contributes to global warming.
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Nitrogen Cycle
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Nitrogen Cycle
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Nitrogen is needed to make proteins and nucleic
acids such as DNA.
Plants take up inorganic nitrogen from the
environment and build protein molecules which are
later eaten by consumers.
 Nitrogen-fixing bacteria change nitrogen to a
more useful form by combining it with hydrogen
to make ammonia. Other bacteria convert
ammonia to nitrites and then nitrates, which can
be taken up by plants to make proteins.
- Members of the bean family (legumes) have
nitrogen-fixing bacteria living in their root
tissue.
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Nitrogen Cycle
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Nitrogen re-enters the environment:
- By death of organisms
- Animal excrement and urinary wastes
Nitrogen re-enters atmosphere when denitrifying
bacteria break down nitrates into N2 and nitrous
oxide (N2O) gases.
- Humans have profoundly altered the nitrogen
cycle via use of synthetic fertilizers, nitrogenfixing crops, and fossil fuels.
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Phosphorus Cycle
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Phosphorus Cycle
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Phosphorus is needed to make DNA, & ATP (the
energy currency of the cell) and other important
biomolecules.
Phosphorus compounds are leached from rocks
and minerals and usually transported in aqueous
form.
 Taken in and incorporated by producers
- Passed on to consumers
 Returned to environment by decomposition
Cycle takes a long time as deep ocean sediments
are significant sinks
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Sulfur Cycle
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Sulfur Cycle
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Most sulfur is tied up in underground rocks and
minerals. Inorganic sulfur is released into air by
weathering and volcanic eruptions.
 Cycle is complicated by large number of
oxidation states the element can assume.
 Human activities release large amounts of sulfur,
primarily by burning fossil fuels.
- Important determinant in acid rain
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