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 energy

6O2 + 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

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 BiosphereThe 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)

The Cycling of Matter in the Biosphere Worksheet and

Diagrams

What do you need to know about each cycle?

Biogeochemical Cycles, Human Impact and Environmental Problems

Assignment

Final Task and Review for Test