Energy in the Environment Energy Roles and Energy Flow

NGSS Standard MS-LS2-e. Conduct an investigation of the cycling of matter among living and nonliving parts of ecosystems to support the explanation of the flow of energy and conservation of matter.

Energy Think back to our discussion of predator- prey relationships. What is the main benefit for the predator in the organism relationship?

Energy The main benefit from a predator-prey relationship for the predator, is that the predator gains food from it’s prey. This food will eventually will be broken down by the predator and use for energy. What is the process that takes food and gives an organism energy?

Energy Energy usage is a need of living things and as a result plays a large role in the environment. All organisms fill out a specific energy role in an ecosystem. The organism’s energy role is determined by how the animal obtains energy and interacts with other organisms.

Energy Roles Producers Consumers Decomposers

Producers Most energy enters ecosystems through sunlight. This energy is then captured by certain consumers and stored as food energy, through photosynthesis. All organisms that produce their own food are called producers. –This includes plants, algae, and some bacteria.

Consumers Obtain their food by feeding on other organisms. Consumers are classified by what they eat. –Herbivores –Carnivores –Omnivores –Scavenger

Decomposers Break down wastes and dead organisms and return the raw materials found in these organisms to the ecosystem. If we did not have decomposers the raw materials of life would stay locked up in organisms and would never be re- circulated in the environment. Serves as the “recyclers” of the ecosystem.

Energy How do you think energy is transferred between organisms?

Food Chains and Food Webs Energy is transferred to from organism to organism. Consumers eat producers, other consumers eat the first consumers and so on… The flow of this energy can be diagramed by food chains and food webs.

Food Chain A series of energy transfer in which one organism eats another and obtains energy. Food chains are not very realistic. Think back to our lion example last week how many food sources did it have?

Food Webs Are multiple overlapping food chains. These are more realistic because organisms can serve as food for many organisms.

Energy After looking at energy transfers do you think energy is available in equal amounts? Think about how energy comes into the ecosystem.

Energy Energy availability is not equal at every level. Organisms will use 90% of the energy they obtain for life functions or lost as heat to the environment. About 10% of the energy stored in an organism will be passed onto the next organism.

Energy Since only 10% of energy is transferred from organism to organism, ecosystems are limited to the number of consumers they can support. Note: just because top level consumers receive less energy when they feed, that does not mean they require less energy. In most cases they require more energy than other consumers.

Review How are consumers classed? How is energy transferred between organisms? What does an energy pyramid represent? How does energy enter an ecosystem? What are food chains and food webs? Which level of the energy pyramid contains the most energy?