unit a. what is the biosphere? narrow zone of the planet that supports life and living organisms...
TRANSCRIPT
Energy and Matter Exchange in the Biosphere
Unit A
What is the BIOSPHERE? Narrow zone of the planet that supports life
and living organisms within it Includes: ocean to lower atmosphere Not included: earths core and upper atmosphere
3 zones1. Lithosphere (land) 2. Hydrosphere (water) 3. Atmosphere (air)
Made up of living (biotic) and non living (abiotic) components
Ex. Biotic = plant and animals Abiotic = geological (rocks, minerals, land) and physical elements (temperature, precipitation, light, air, gas)
Organized into levels for study Closed system which means matter (nitrogen,
oxygen etc.) is not exchanged with surroundings it has to be recycled but energy is constantly flowing
Levels of Biosphere
Made up of
Made up of
Made up of
Made up of
ENERGY FLOWS AND MATTER CYCLES
Energy Flow in the BiosphereEnergy enters the ecosystem is passed
from organism to organism and is used up or exits the system via heat
Source of earth’s energy is the sun
Energy Flow in the Biosphere
30% reflected by clouds or surface of earth
40% heats atmosphere and earth’s surface
25% heats and evaporates water
1% generates wind
>0.02 % is used by plants to create useable energy
30% of sun energy is reflected by clouds or the earths surface
ALBEDO EFFECTthe extent at which material can reflect
sunlight The greater the ability of a material to reflect
sun the higher the albedo therefore the lower the energy absorption
The lower the ability of a material to reflect sun the lower the albedo therefore the higher the energy absorption
Areas that are snow covered, cloudy, dusty or are desert or deforested areas all have a higher albedo (more reflection) therefore have lower energy absorption
PHOTOSYNTHESIS AND CELLULAR RESPIRATION
The 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
convert energy6O2 + C6H12O6 --> 6H2O + 6CO2 + energy
These two processes are complementary Because they both use 02 and C02 there
should be a balance of those gases in the environment
0.023% of suns energy is used by living organisms
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/webs1. 1st Trophic Level = Producers = Autotrophs2. 2nd Trophic Level = Primary Consumers =
Heterotrophs3. 3rd Trophic Level = Secondary Consumers =
Heterotrophs
1st Trophic LevelBottom of the food chainPlants, trees, grasses, algae etc. Autotroph
Can make own “food” (energy) Producer
Takes direct sun energy and turns it into usable energy using the process of photosynthesis
2nd Trophic LevelAnimals lower on the food chain (ie
herbivores)Moose, gopher, deer, mice etc.Heterotroph
Does not make own “food” Primary consumer
Eats a producers
3rd Trophic LevelAnimals higher on the food chain (ie
carnivores and omnivores, decomposers)Bear, Wolf etc.Heterotroph
Does not make own “food”Secondary consumer
Eats producers and/or primary consumers
Put labels on diagramspg 23 Food Web
Can organisms fit into more than one level/category? Why?Why not? Is this a good or bad thing?
Do you think the amount of energy increases or decreases as you move up the trophic levels?
JUSTIFY
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
How do humans interfere with natural energy flow
Pg 33
Chemosynthetic Food Chains
Exist in ecosystems where there is little to no solar energy Caves, deep ocean, extreme environments
A chemotroph (bacteria) replaces the autotroph in the first trophic level of the food chain
Chemotrophs use energy from a variety of other sources Chemical energy from minerals, thermal energy
from the core
Food Chains Handout
ECOLOGICAL PYRAMIDS
(pg 28-32)
Visuals that help represent the energy flow in a system
Three types of pyramids1. Pyramid of Biomass
A measure of total dry mass of all living things in the ecosystem
2. Pyramid of EnergyA measure of energy at each level
3. Pyramid of NumbersA count of the number or organisms at each level
Stability in an ecosystem
Ecosystem is a community of species and its physical and chemical environment
Organisms are interconnected and rely on each other
What would make a stable ecosystem?
Stability in an ecosystem
Stable ecosystems that small changes would not cause major disruptions or disturbances to other organisms
The greater the biodiversity the greater the stability
WHY?Read “Why biodiversity is a good thing” and answer
the questions
What factors largely determine an areas biodiversity?
Why do tropical rainforests usually have high biodiversity?
Why would deserts and arctic have low biodiversity?
Why do areas of high biodiversity seem to continue to function well and species have good chance to survive?
In areas of high biodiversity, why is there little population fluctuation?
Why are areas of low biodiversity at such high risk of extinction? Give a specific example.
Why is loss of biodiversity a “vicious cycle”?
Is Biodiversity a “good thing”? Justify
Why is biodiversity a good thing?
More organisms mean more complex and developed food webs
The less vulnerable to changes in the ecosystem Removal of a species or drastic weather changes Domino effect (pg 9 cause and effect Sea Urchins and
Whooping Cranes)
Creating a Food WebAssignment
ENERGY FLOWS AND
MATTER CYCLES
Matter Cycling in the Biosphere
The biosphere is a closed system so every living thing depends on the matter already available on earth It is possible that a carbon atom that helped make up a T
Rex 70 million years ago can be somewhere in your bodyNew matter is not introduced so nutrients
are cycled and recycled between the environment and organisms These cycles are called the BIOGEOCHEMICAL
CYCLES
Biogeochemical Cycles
Matter is mostly made up of the following elements and there is a specific cycle for each: Carbon Hydrogen Oxygen Nitrogen
These four elements make up all basic compounds used by living organisms Carbohydrates (energy for cells) Lipids (storage in cells) Proteins (structure in cells) Nucleic Acids (genetic material in cells)
Biogeochemical Cycles
Cycling of matter through biotic and abiotic parts of ecosystems allow all organisms including plants to obtain essential nutrients
At each step in every cycle, substances are temporarily stored in nutrient reservoirs (organisms, soil, air, water)
O, C, N, S travel easily in both water in airP and Fe do NOT travel in atmosphere but in
soil and waterSimilar and interrelated
Disruptions in one can affect another
The Cycling of Matter in the Biosphere Worksheet and
Diagrams
Nutrient ReservoirsNutrients are either stored or move from
reservoir to reservoirCarbon 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
Hydrological CycleWater
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
Carbon CycleCarbon
Key element for living thingsRapid Cycling
Plants animals and decomposers play important role
Carbon CycleSlow Cycling
3 main reservoirs of carbon in the atmosphere, oceans, earth’s crust
Phosphorus CyclePhosphates
Key elements in making ATP and calcium in bones Animals obtain phosphorus by consuming foods
such as milk, grain and meal Producers such as plants and algae can only use it
in forms of phosphates which dissolve in waterShort Term Cycle
living organisms
Phosphorus CycleLong Term Cycle
Rocks in Earth’s crust
Nitrogen CycleNitrogen
Makes up 78.1% of atmosphere Essential part of proteins and DNA
Nitrogen Fixation Process to convert atmospheric nitrogen into useable
ammonium by bacteria or lightningAmmonification
Process of converting ammonium into nitrite then useable nitrate by bacteria so plant can use it
Denitrification 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- FertilizerWater-burning fossil fuels add sulfuric acid
and nitric acid
Biogeochemical Cycles, Human Impact and Environmental Problems
Assignment
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
Transfers of energy from producers to consumers affects biogeochemical cycles
Balance of Matter and EnergyEarth is similar to organisms must
maintain conditions within certain limits to ensure a state of balance (EQUILIBRIUM)
Gaia hypothesis-James Lovelock- Biosphere regulates itself, needs constant input of
energy and cycling of nutrients
Ecosystem Productivity
Is the 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
Biosphere 2Large scale biosphere experiment
constructed closed systemsSeveral months until the oxygen levels
dropped and carbon dioxide levels roseProved that energy and matter exchange
is extremely complexResearch facility showed that delicate
balance
http://www.b2science.org/
NASA: Advanced Life Support (ALS)
Research plants grown in space for oxygen and food
Conversion of waste into usable energySelf sustaining colonies for humansDevon Island (Canada) hypothetical colony
on Mars
http://www.nasa.gov/centers/ames/research/technology-onepagers/advanced-life-support.html
Imagine that in the future humans live in domed cities protected from high UV radiation. Describe all the necessary
conditions that must exist in this closed system for life to continue. Include the kind of dome needed and the sources of
energy, water, carbon dioxide and oxygen. Also include a plan for cycling nitrates and phosphates and recycling wastes.
Final Task and Review for Test