1. Warm-up In your comp. notebook answer the following: Where does energy in living systems come from? How is it transferred from one organism to another?

2. Energy in the Biosphere Ch. 3.2: Energy, Producers and Consumers Ch. 3.3: Energy Flow in Ecosystems

3. 3.2 Energy, Producers, and Consumers All living systems operate by using energy Organisms need energy for: – Growth – Reproduction – Metabolic processes

4. How do we obtain energy? Can organisms create energy? For most organisms the sun provides the ultimate energy source However research has shown that some organisms obtain energy from chemical compounds – Ex: chemosynthetic bacteria

5. Primary Producers Autotrophs: an organism that is able to capture energy from the sun or chemicals and use it to produce its own “food” – They do this by assembling inorganic compounds into organic molecules Primary producers are the first producers of energy-rich compounds that are later used by other organisms

6. Life with light The most common primary producers use energy from sunlight in the process of photosynthesis CO 2 + H 2 O  C 6 H 12 O 6 + O 2

7. Life without light Some primary producers harness energy from compounds like hydrogen sulfide Chemosynthesis: process in which chemical energy is used to produce carbohydrates + CO 2 +H 2 S + 0 2  C 6 H 12 O 6 + sulfur compounds Chemical energy

8. Heterotrophs aka Consumers Many animals cannot directly harness energy using the sun or chemosynthesis. They are known as heterotrophs Since heterotrophs ingest other organisms to obtain energy they are also called consumers.

9. Types of Consumers Carnivores Detritivores Decomposers Scavengers Herbivores Omnivores

10. Ch.3.3 Energy Flow in Ecosystems How does energy flow through ecosystems? What do the three types of ecological pyramids illustrate?

11. Food Chains and Food Web Energy flows through an ecosystem only one way: primary producers  consumers A food chain is a series of steps in which organisms transfer energy by eating and being eaten.

12. When chains are longer… an example, Aquatic Food Chain In some aquatic food chains, primary producers are a mixture of floating algae called phytoplankton and attached algae.

13. Food Web Many animals eat more than one type of food. A network of feeding interactions in an ecosystem is called a food web Example is from southern hemisphere of Earth, ie penguins and orca.

14. Decomposers and Detritivores Decomposers and detritivores also play a role in food web – How?

15. Food Webs and Disturbance Food webs are complex, so it is hard to predict how a disturbance in the ecosystem will affect the organisms in it

16. Trophic Level and Ecological Pyramids Every step in a food chain or web is called a trophic level Ecological pyramid Shows relative amount of energy or matter in each level 1.Pyramids of energy 2.Pyramids of biomass 3.Pyramids of number

17. Pyramids of Energy Between each trophic level- energy is lost, mainly released as heat Average -> about 10% of the available energy is transferred from one trophic level to the next. Pyramids of energy show the relative amount of energy available at each trophic level of a food chain or web

18. Pyramids of numbers and biomass The total amount of living tissue within a given trophic level is called its biomass A pyramid of biomass shows the relative amount of living organic material available at each level A pyramid of numbers shows the relative number of individual organisms at each trophic level

19. Any Questions? At the end of your notes: Go to page 78 Answer 3.3 Section Assessment Questions #1 & #2.