Energy Flow through an Ecosystem

Energy Flow through an Ecosystem
Explain how most living things depend on the sun as their ultimate energy source.
“Without the sun, all life dies” (Konacq, 2014). Plants need to photosynthesize the food they need for growth. The food chain is also affected. Photosynthesis is needed to make nutritious food that animals depend on for survival (Konacq, 2014). Without sunshine, “all plants die” (Konacq, 2014). Because plants support the global food chain for all life, without plants, “all animals would die” (Konacq, 2014). The sun also aids in keeping the earth at a reasonable temperature and in the past, sunshine has helped make fossil fuels which we use today (Konacq, 2014).
Describe the characteristics that make water so unique and essential for life on Earth. 1. Water molecules are polar. They have a slightly positive charge on one side and a slight negative charge on the other. Water carries materials to and from cells and it dissolves polar or ionic substances (Cunningham and Cunningham, 2013). 2. Water is the only liquid that is inorganic and occurs in nature. It occurs normally and at temperatures that are suitable for life (Cunningham and Cunningham, 2013). 3. Water molecules stick together cohesively. It adheres to surfaces and can be drawn into small channels (Cunningham and Cunningham, 2014). 4. Water expands when it crystalizes. If the temperatures happen to fall below freezing, the surface layers of bodies of water cool faster and freeze before deeper water. Floating ice insulates the bottom layers keeping most of the water bodies liquid. In the winter, this helps keep many aquatic organisms alive (Cunningham and Cunningham, 2013). 5. Water uses a great deal of heat to convert from a liquid to vapor. Evaporating water then becomes an efficient way for organisms to shed access heat (Cunningham and Cunningham, 2013). 6. Water has a high specific heat. A great deal of heat is absorbed prior to it changing temperature. Therefore, it helps to balance out global temperatures, keeping it warm in the winter and cooler in the summer (Cunningham and Cunningham, 2013).
Describe the roles played by producers, consumers, and decomposers in an ecosystem and the interactions among them.
A producer is an organism that synthesizes food molecules from inorganic compounds by using an energy source that is external (Cunningham and Cunningham, 2013). Organisms that feed on other organisms and their remains and utilize this for nutrients and energy are consumers (Cunningham and Cunningham, 2013). Decomposers are bacterium or fungus that breaks down complex organic material into much smaller molecules (Cunningham and Cunningham, 2013).
“At a basic functional level, ecosystems generally contain primary producers capable of harvesting energy from the sun by photosynthesis and of using this energy to convert carbon dioxide and other inorganic chemicals into the organic building blocks of life. Consumers then feed on this captured energy, and decomposers not only feed on this energy, but also break organic matter back into its inorganic constituents, which is ready to be used again by producers. These interactions among producers and the organisms that consume and decompose them are called trophic interactions, and are composed of trophic levels in an energy pyramid” (Ellis, 2014).
Explain how the flow of energy and the cycling of matter bind together the structural components of an ecosystem. “Energy input to ecosystems drives the flow of matter between organisms and the environment in a process known as biogeochemical cycling. The biosphere provides an example of this, as it interacts with and exchanges matter with the lithosphere, hydrosphere and atmosphere, driving the global biogeochemical cycles of carbon, nitrogen, phosphorus, sulfur and other elements. Ecosystem processes are dynamic, undergoing strong seasonal cycles in response to changes in solar irradiation, causing fluctuations in primary productivity and varying the influx of energy from photosynthesis and the fixation of carbon dioxide into organic materials over the year, driving remarkable annual variability in the carbon cycle, the largest of the global biogeochemical cycles. Fixed organic carbon in plants then becomes food for consumers and decomposers, who degrade the carbon to forms with lower energy, and ultimately releasing the carbon fixed by photosynthesis back into carbon dioxide in the atmosphere, producing the global carbon cycle” (Ellis, 2014).
“The biogeochemical cycling of nitrogen also uses energy, as bacteria fix nitrogen gas from the atmosphere into reactive forms useful for living organisms using energy obtained from organic materials and ultimately from plants and the sun. Ecosystems also cycle phosphorus, sulfur, and other elements. As biogeochemical cycles are defined by the exchange of matter between organisms and their environment, they are classic examples of ecosystem-level processes” (Ellis, 2014).

References
Cunningham, W. P., & Cunningham, M. A. (2013). Principles of Environmental Science: Inquiry & Applications (7th ed.). New York, NY: McGraw Hill.
Ellis, E. (2014, September 24). Ecosystem. In The Encyclopedia of Earth. Retrieved October 4, 2014, from http://www.eoearth.org/view/article/152248/
Konacq. (n.d.). Why is the sun the ultimate source of energy for all living things? In Answers. Retrieved October 4, 2014, from http://www.answers.com/Q/Why_is_the_sun_the_ultimate_source_of_energy_for_all_living_things