U11: Energy Flow

ECDCICA

What’s for Lunch?

• Black Bear • Raccoon

What’s for Lunch?

• Ruffed Grouse • Hawk

Trophic Level• Ecosystems are structured by who eats whom.

A trophic level is the position that an organism occupies in a food chain- what it eats and what eats it. Every organism belongs to at least one feeding level or tropic level.

Energy Pyramid• A graphical representation to show the

relationship between energy and the trophic levels of a given system is an Energy Pyramid.

Law of Thermodynamics• As chemical energy

flows through an ecosystem heat energy is lost at each trophic level. Only 10% of the chemical energy transfers and 90% is lost as heat energy.

• This heat energy loss is displayed in the Energy Pyramid.

Law of Thermodynamics

Law of Thermodynamics

Trophic Level

• Producers make their own food through photosynthesis or chemosynthesis

• Examples: grass, fern, cactus, flowering plant, tree, algae, some bacteria

Trophic Level

• Consumers get their energy by eating producers or other consumers.

• Examples: mouse, starfish, turtle, paramecium, sponge, ant, human

Trophic Level• Decomposers break

down dead organisms in an ecosystem and return the nutrients to soil, water and air. Converts bond energy from dead and decaying organisms into heat. Examples: fungus, bacteria

What can make their own food?

Producers! Autotroph auto means self

troph means nourish• An organism that produces, or makes

their own food. Autotrophs are also called producers.

Cannot make their own food

• Heterotroph hetero means other troph means nourish

• An organism that obtains its energy by the consumption of or decaying of other organisms.

• Heterotrophs are also called consumers (consumption) or decomposers (decaying).

Types of organismsA. Consumers in an ecosystem

• Primary Consumer – The first consumer in a food chain/ food web and consumes a producer.

• Herbivores or plant eater

• Secondary Consumer – The second consumer in a food chain/food web.

• Tertiary Consumer – The third consumer in a food chain/food web.

What it eats – niche in the food web

• Herbivore – An organism that eats plants, nuts, berries ie. rabbit, deer

• Omnivore – An organism that eats plants and animals ie.

black bear, human

• Carnivore – An organism that eats animals ie. wolf, hawk, whale

• Scavenger – An organism that feeds off of dead animals that they did not hunt or kill themselves. ie. vulture

Where are the Omnivores?

Predator vs Prey • Predator – An organism that feeds on what it

hunts and kills ie. coyote • Prey – An organism that is hunted and killed for

food ie: mouse

• Is a producer prey? ______ • Can an organism be both prey and predator? ___

Food Chain – A pathway in which energy flows through an ecosystem.

Food Web – All possible pathways in which energy flows through an ecosystem.

Energy flow… how it begins

• Photosynthesis – Conversion of sun’s energy to chemical energy (food). Performed by producers.

6CO2 + 12H2O + Sunlight energy C6H12O6 + 6O2 + 6H20

(C6H12O6 = glucose, food energy, chemical energy,

potential energy - in bonds)

• Cellular Respiration – Process by which chemical energy (food) is converted to usable energy. Performed by producers, consumers and decomposers!

• C6H12O6 + 6O2 + 2ATP 6CO2 + 6H2O + 38ATP (usable energy for cells)

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Water is released

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2 ATP

Energy Flow

Energy in a Pond

Circle the Autotrophs and draw a rectangle around the HeterotrophsDraw an arrow to all organisms that would be an energy source for decomposersLabel PH – for all organisms that perform Photosynthesis Label CR – for all organisms that perform Cellular RespirationLabel 1E – for the primary energy source in this ecosystemLabel 1C - primary consumers, Label 2C – secondary consumers & Label 3C- tertiary consumers

List abiotic factors in pond __________________________________________________

Energy Flow - Label in the diagram: chemical energy transfer (10%) or heat energy loss (90%)