ECOSYSTEMS AND ENERGY
CHAPTER 2
P.52-60
ENERGYTHE ABILITY TO DO
WORK OR CAUSE CHANGE
TYPES OF ENERGY
1. POTENTIALSTORED ENERGY
(BEFORE THE PITCHER RELEASES THE BALL)
2. KINETICENERGY OF MOTION
(THE PITCHED BALL)
3. CHEMICALFROM ORGANIC MOLECULES, NUTRIENTS
(PHOTOSYNTHESIS, CHEMOSYNTHESIS)
4. FREEENERGY NEEDED FOR A CELL TO WORK
(SUCH AS FROM ATP)
*EAT FOODGLUCOSEATP*
ORGANISMS THAT NEED ENERGY
• AUTOTROPHS
MAKE THEIR OWN FOOD SUCH AS PLANTS USING LIGHT FOR PHOTOSYNTHESIS
ARE CALLED
PHOTOAUTOTROPHS
ENERGY USING CHEMICALS (CHEMOSYNTHESIS) SUCH AS BACTERIA ARE
CALLEDCHEMOAUTOTROPHS
• HETEROTROPHS
CANNOT MAKE THEIR OWN FOOD AND MUST OBTAIN IT SUCH AS ANIMALS,
FUNGI AND MOST BACTERIA
**BOTH AUTOTROPHS AND HETEROTROPHS USE CELLULAR RESPIRATION IN
ORDER TO RELEASE ENERGY FOR CELLS TO STAY ALIVE (GLUCOSEATP)
**BOTH STORE ENERGY (CHEMICAL ENERGY) AND USE SOME OF IT TO DO WORK
(FREE ENERGY)
ECOSYSTEM STRUCTURE
1. PRODUCERS (AUTOTROPHS SUCH AS
PLANTS)
2. CONSUMERS (HETEROTROPHS SUCH AS
HERBIVORES, CARNIVORES, OMNIVORES)
3. DECOMPOSERS (HETEROTROPHS SUCH AS
BACTERIA, FUNGI)
*THESE BREAKDOWN AND RECYCLE MATTER FOR NUTRIENTS*
FOOD CHAINS
• SHOW ENERGY FLOW BASED UPON WHAT
ORGANISMS EAT
• EXAMPLE: GRASSRABBITSNAKEHAWK
TROPHIC LEVELS
•
•
•
•
•
PRODUCERUSUALLY PLANTS
CONSUMERPRIMARY/1STORDER
CONSUMERSECONDARY/2ND ORDER
CONSUMERTERTIARY/3RDORDER
CONSUMERQUATERNARY/4TH ORDER
FOOD WEBS
• MADE UP OF MANY FOOD CHAINS
• SHOWS THE INTERACTIONS BETWEEN THE
MEMBERS OF AN ECOSYSTEMFOR ENERGY
AND NUTRIENTS
• FROM PRODUCERS TO CONSUMERS
(BOTTOM TO TOP)
2 LAWS OF THERMODYNAMICS
P.57-60
2 LAWS OF THERMODYNAMICS
1. ENERGY CANNOT BE CREATED OR DESTROYED
BUT CAN CHANGE FORM (LAW OF
CONSERVATION OF ENERGY)
2. SYSTEMS TEND TO CHANGE IN A WAY THAT
INCREASES DISORDER (ENTROPY) OF THE
SYSTEM AND ITS SURROUNDINGS
– FREE ENERGY INCREASES, ENTROPY DECREASES
– FREE ENERGY DECREASES, ENTROPY INCREASES
*ORGANISMS OVERCOME THIS TENDENCY FOR
INCREASED ENTROPY BY OBTAINING ENERGY
PYRAMIDS OF
ENERGY, BIOMASS, AND NUMBERS
• AT THE BASE OF EACH ARE THE PRODUCERS
FOLLOWED BY THE CONSUMERS
• AS YOU GO FROM THE BOTTOM TO THE TOP,
ALL 3 DECREASE
Levels of Organization
Biosphere
Ecosystem 
Community 
Population 
Organism
Biosphere
• Broadest, most inclusive level
• Thin volume of Earth and its atmosphere that
supports all life
• 20km (13mi) thick
• 8-10 km (5-6mi) deep
into oceans
• Comparable to skin
only of ENTIRE apple
Ecosystems
• Includes all organisms and the non-living
environment found in a particular place
• Ex: Pond
– Living
• Fish, aquatic
plants, algae,
bacteria, etc
– Nonliving
• Water, sunlight,
rocks
Community
• All interacting organisms living in an area
• Look at how species interact
• How interactions
influence nature of
community
• Ex: Pond
– How fish
interact with
plants, algae,
bacteria
Populations
• Includes all members of a species that live in
one place at one time
• Ex: Pond
– Rainbow trout
of THAT SPECIFIC
POND
Organism
• Simplest level
• Look at behavioral adaptations that allow
organism to overcome
obstacles
• Ex: Pond
– One specific
rainbow trout