ENVIRONMENTAL SCIENCE

1. ENVIRONMENTAL SCIENCE Chapter 5 How Ecosystems Work 5.1 Energy Flow in Ecosystems

2. 5.1 Energy Flow in Ecosystems Objectives • Describe how energy is transferred from the sun to producers and then to consumers. • Describe one way in which consumers depend on producers. • List two types of consumers. • Explain how energy transfer in a food web is more complex than energy transfer in a food chain. • Explain why an energy pyramid is a representation of trophic levels.

3. Life Depends on the Sun • The ultimate source of energy for almost all organisms is the sun. • Energy from the sun enters an ecosystem when a plant undergoes photosynthesis – the process used by plants to convert simple inorganic molecules into more complex organic molecules via solar energy. • Solar energy drives a series of chemical reactions that require carbon dioxide and water resulting in the production of carbohydrates. • Carbohydrates are a form of chemical energy. • When an animal eats a plant, some energy is transferred from the plant to the animal.

4. http://thoughtchalk.com/2011/07/01/genetic-engineering-and-photosynthesis-in-animals/http://thoughtchalk.com/2011/07/01/genetic-engineering-and-photosynthesis-in-animals/

5. http://bioweb.uwlax.edu/bio203/2011/klees_ther/nutrition.htm

6. Life Depends on the Sun • A producer (a.k.a. autotroph) is an organism that makes its own food. • Consumers are organisms that get their energy by eating other organisms. • Consumers are a type of heterotroph – an organism that has to get its organic material from an outside source. • Producers get their energy directly from the sun. • Consumers get their energy indirectly from the sun by consuming producers or consumers.

7. http://www.propane.pro/category/lpg/ http://www.heraldsun.com.au/opinion/tricky-path-for-premier-ted-baillieu-on-grazing/story-e6frfhqf-1225971227522

8. Life Depends on the Sun • Thermal vent communities are an exception to the norm of solar dependence. • Thermal vent communities exist in the total darkness of the deep ocean and bacteria are the producers using hydrogen sulfide as the energy source. • Hydrogen sulfide is present in the hot water that escapes from the cracks in the ocean floor. • The use of hydrogen sulfide instead of light energy is called chemosynthesis.

9. http://deepseanews.com/2012/02/the-marine-biology-bucket-list/http://deepseanews.com/2012/02/the-marine-biology-bucket-list/ http://www.marinebio.net/marinescience/04benthon/dsvents.htm

10. What Eats What • Herbivores (deer and cows) are consumers that only eat producers. • Carnivores (lions and hawks) are consumers that eat only other consumers. • Omnivores (humans and raccoons) eat both plant and animal matter. • Decomposers (for example, many bacteria and fungi) are consumers that get their food by breaking down dead organisms. • Decomposers are essential for recycling of nutrients.

11. Cellular Respiration: Burning the Fuel • Cellular respiration is the process of breaking down food to yield energy. • Cells absorb oxygen and use it to release energy from food. • The equation for cellular respiration is essentially the opposite as that for photosynthesis. http://bhavanajagat.com/2012/05/25/spiritualism-the-science-of-matter-energy-life-and-spirituality/

12. Energy Transfer • Each time one organism eats another organism, a transfer of energy takes place. • Food chains, food webs, and trophic pyramids may be used to study the transfer of energy through an ecosystem. • A food chain is a simple sequence in which energy is transferred from one organism to another. • A food web is an illustration that shows the many possible feeding relationships in an ecosystem with arrows going from what is consumed to what may consume the item. • Each step in the transfer of energy through a food chain or food web in an ecosystem is known as a trophic level.

13. http://www.tutorvista.com/content/biology/biology-ii/environment-and-environmental-problems/ecological-balance.phphttp://www.tutorvista.com/content/biology/biology-ii/environment-and-environmental-problems/ecological-balance.php http://www.pride2.org/NewPrideSite/Asia/Lesson7/FoodWebs.html

14. Energy Transfer • Each time energy is transferred from one organism to another, some energy is lost as heat and less energy is available to organisms at the next trophic level. • Some energy is lost during cellular respiration. • About 90% of energy at each trophic level is used to maintain life functions. • The remaining 10% of energy becomes part of the organism’s body and is stored in its molecules to be passed on to the next trophic level.

15. Energy Transfer • Energy pyramids illustrate the relative amount of energy or biomass at each trophic level in an ecosystem. • The lowest trophic level, containing the most energy/biomass, is the producer level. • Producers are consumed by primary consumers (a.k.a. herbivores). • Primary consumers are consumed by secondary consumers. • Tertiary consumers consume secondary or other tertiary consumers. • Because so much energy is lost at each level, the number of trophic levels for any given ecosystem is fairly low.

16. http://bio1152.nicerweb.com/Locked/media/ch55/pyramid-production.htmlhttp://bio1152.nicerweb.com/Locked/media/ch55/pyramid-production.html

17. http://legacy.owensboro.kctcs.edu/gcaplan/eco/Note%20Withgott/ECO%20NOTE%20K%20Species%20Interaction.htmhttp://legacy.owensboro.kctcs.edu/gcaplan/eco/Note%20Withgott/ECO%20NOTE%20K%20Species%20Interaction.htm