The Flow of Energy Essay Example for Free

The Flow of Energy Essay Energy can neither be created nor destroyed. This is what the law of conservation of energy states. In our environment, energy flows in one form to another through the different natural processes. In ecosystems, some energy is converted into nutrients, which is then passed from one organism to another. The model used to show the transfer of energy and nutrient from one organism to another is called food chain. Sunlight is the main source of energy here on earth. Energy from sunlight, called solar energy, is converted into chemical energy by plants through a process called photosynthesis. Plants also make use of nutrients found in the soil to produce their food. That plants are able to produce their own food is why they are called the producers in the food chain. Animals cannot make their own food and get the energy and nutrients they require from eating plants or other animals. Hence, they are called consumers. Animals that eat only plants are called herbivores; animals that eat only other animals are called carnivores; and animals that eat both plants and other animals are called omnivores. In the food chain, animals that feed on plants are the first level consumers and animals that feed on them are the second level of consumers. There can be up to three to four levels of consumers in the food chain, after which decomposers, such as worms, bacteria and fungi, break down the wastes and dead organisms as their food source and return nutrients back into the soil. Energy transferred through the food chain does not have a fixed amount. Producers, for example, only converts about three percent of the energy absorbed from the sun into chemical energy. The actual energy and nutrient transferred from one organism to another gets lower with each transfer. In general, only â€Å"about ten percent of the energy from one level of a food chain makes it to the next† (KEEP, n. p. ). The energy and nutrients, however, are not lost with each transfer. It is just that organisms are unable to â€Å"digest† all nutrients from what they eat. The undigested nutrients are excreted as wastes. Organisms may also have used some of the energy they received, by converting chemical energy into mechanical energy in cases of animals, and are unable to transfer all of the energy to the next level in the food chain. The energies used by animals are eventually converted into heat energy. Works Cited â€Å"Energy flow in ecosystems. † 2002. Energy through our lives. K-12 Energy Education Program (KEEP), University of Wisconsin Stevens Point. 7 July, 2008. http://www. uwsp. edu/cnr/WCEE/keep/Mod1/Flow/foodchains. htm