Transfer of Energy

1. Transfer of Energy S7L4b Explain in a food web that sunlight is a source of energy and that this energy moves from organism to organism.

2. Ecosystems include living and non-living factors, and humans are a key component. • Living factors are called biotic. • Non-living factors are called abiotic.

3. Energy Flow • The fuel that gives your human body, a part of the animal kingdom, energy comes from the plants and animals you consume. This living material is called biotic matter. • Biotic matter and the energy contained in it ISrecycled through the ecosystem (including you).

4. Elements, chemical compounds and other sources of matter pass from one state to another through the ecosystems. • The cycle is as follows: • Producer to primary consumer, to secondary consumer to decomposer

5. Humans Take and Give Energy • Humans are top consumers. • We essentially have no competition for resources. • We eat all manner of animals and plants, which we digest and excrete. • Humans do take energy out of the ecosystem by consuming biotic matter and do put energy back into it through waste products and, ultimately, through decomposition.

6. Trophic Levels • The amount of energy decreases as organisms go up the food chain. • A trophic level is the position occupied by an organism if a food chain

7. Plants are found at the base of the energy pyramid and comprise the first tropic level of the food chain. • They are called producers. • They produce their own energy by making their own food, using photosynthesis. • The energy that drives the food making process (photosynthesis), comes from the Sun.

8. Primary consumers are above the producers. • They make up the second trophic level. • These organisms eat plants • Sometimes we are a primary consumer, when we eat fruits and vegetables. • Secondary consumers are next, to occupy the third trophic level. • This third level eat the primary consumers. • Tertiary consumers are the top trophic level.

9. The greatest concentration of energy exists at the base of the pyramid, with plants. • Herbivores like the grasshopper and herring, are getting a highly concentrated source of energy when they consume their food. • Energy is used up fairly quickly but it is NOT destroyed. It simply changes forms.

10. Energy that comprise the leaves become a part of the grasshopper, giving it fuel and allowing it to grow, to repair itself and to reproduce. • The plant energy is used to drive physical processes and is dispersed as heat. • Grasshopper gets attacked by a hungry opossum and is killed. Opossum eats the grasshopper. • The amount of energy is the same, it is just less efficient.