SMES - Science, Matter, Energy, and Systems Module Overview

Science, Matter, Energy, and Systems

Mining materials image While energy flows in a complex, but ultimately one-way path through nature, materials are endlessly recycled. The major material cycles (water, carbon, nitrogen, phosphorus, and sulfur) are critically important to living organisms. As humans interfere with these material cycles, we make it easier for some organisms to survive and more difficult for others. Often, we're intent on manipulating material cycles for our own short-term gain, but we don't think about the consequences for other species or even for ourselves in the long term. Clearly, it's important to understand these environmental systems and to take them into account in our public policy.

Essential Questions

How does carbon move through the carbon cycle?
How have humans impacted the nitrogen cycle?
Why is phosphorous not able to be transported to different locations during the phosphorous cycle?
How are humans affecting the sulfur cycle?
Why is phytoplankton such an important part of the ocean food chain?

Key Terms

Absorption: The net movement (transport) of water and solutes from outside a cell or an organism to the interior.

Photosynthesis: The biological process that captures light energy and transforms it into the chemical energy of organic molecules (such as glucose), which are manufactured from carbon dioxide and water. Photosynthesis is performed by plants, algae, and several kinds of bacteria. The equation for photosynthesis is 6H₂O + 6CO₂ -‐> C₆H₁₂O₆ + 6O₂

Closed System: a system that does not exchange energy with its surroundings

Law of Conservation of Matter: the principle that in any closed system subjected to no external forces, the mass is constant irrespective of its changes in form; the principle that matter cannot be created or destroyed. Also called the law of conservation of mass, conservation of matter.

Nutrient cycles or biogeochemical cycles: describe the movement of nutrients throughout ecosystems (movements between Earth's abiotic and biotic systems). The word biogeochemical is a combination of bio ("life") geo ("earth"), and chemical ("elements or compounds that cycle through the living and nonliving world")

Water Cycle (hydrologic cycle): the circulation of the earth's water, in which water evaporates from the sea into the atmosphere, where it condenses and falls as rain or snow, returning to the sea by rivers or returning to the atmosphere by evapotranspiration

Carbon Cycle: The continuous process by which carbon is exchanged between organisms and the environment. Carbon dioxide is absorbed from the atmosphere by plants and algae and converted to carbohydrates by photosynthesis. Carbon is then passed into the food chain and returned to the atmosphere by the respiration and decay of animals, plants, and other organisms. The burning of fossil fuels also releases carbon dioxide into the atmosphere.

Aerobic respiration: The process by which cells use oxygen to break down organic molecules with the release of energy that can be used for biological work.

Hydrates: any of a class of compounds containing chemically combined water. In the case of some hydrates, as washing soda, Na₂CO₃⋅ 10H₂O, the water is loosely held and is easily lost on heating; in others, like sulfuric acid, SO₃⋅ H₂O, or H₂SO₄, it is strongly held as water of constitution.

Haber-Bosch process: Referred to by some as the most important technological advance of the 20th century, the Haber-Bosch process fixes nitrogen from the air with hydrogen from natural gas to produce ammonia, a critical component of modern fertilizers. It was the first industrial process to use high pressure to promote a chemical reaction.

Nitrification: Oxidation of ammonium (NH₄⁺) ions into nitrite (NO₂^-‐) ions and then nitrate (NO₃^-‐) ions by microorganisms in soil and water. Nitrate ions are absorbed by the plants as essential nutrients and, with the help of oxygen, converted (synthesized) into plant protein (amino acids).

Ammonification: The dead biomass of plants, animals, and microorganisms contains large concentrations of organically bound nitrogen in various forms, such as proteins and amino acids. The process of decomposition is responsible for recycling the inorganic constituents of the dead biomass and preventing it from accumulating in large unusable quantities. Decomposition is, of course, mostly carried out through the metabolic functions of a diverse array of bacteria, fungi, actinomycetes, other microorganisms, and some animals. Ammonification is a particular aspect of the more complex process of organic decay, specifically referring to the microbial conversion of organic nitrogen into ammonia (NH₃) or ammonium (NH₄⁺).

Nitrogen fixation: Process by which free nitrogen (N₂) is extracted from the atmosphere and converted (fixed) into nitrogen compounds which are plant nutrients (fertilizer). In nature, this process is carried out by unique bacteria (present in the root nodules of legumes such as beans and peas), blue-green algae, and lightning.

Nutrient cycle: Pathway of a nutrient through an ecosystem from assimilation (transformation into living tissue) by organisms to release by decomposition. In other words, the path of a nutrient through an ecosystem from living to non-living things and back again.

Assimilation: the incorporation of a substance into the cells of an organism.

Denitrification: A chemical process in which nitrates in the soil are reduced to molecular nitrogen, which is released into the atmosphere. This process is affected by the bacterium Pseudomonas denitrificans, which uses nitrates as a source of energy for other chemical reactions in a manner similar to respiration in other organisms.

Acid deposition or acid rain: Any precipitation, including snow, that contains a heavy concentration of sulfuric and nitric acids. This form of pollution is a serious regional environmental problem in many large urban and industrial areas. Automobiles, certain industrial operations, and electric power plants that burn fossil fuels emit the gases sulfur dioxide and nitrogen oxide into the atmosphere, where they combine with water vapor in clouds to form sulfuric and nitric acids.

Phosphorus cycle: Inorganic phosphates (PO₄³⁻, HPO₄²⁻, or H₂PO^{4 −}) are absorbed by plants from the soil and bodies of water and eventually pass into animals through food chains. Within living organisms phosphates are built up into nucleic acids and other organic molecules. When plants and animals die, phosphates are released and returned to the abiotic environment through the action of bacteria.

Influx: commonly used in describing biogeochemical cycles to refer to the difference between the number of elements entering a reservoir and the amount leaving the reservoir.

Nitrogen-fixing bacteria: Prokaryotes that fix atmospheric nitrogen (N₂) to ammonia (NH₃) by nitrogen-fixing bacteria and cyanobacteria; part of the nitrogen cycle. Often living as mutualists with root nodules of legume plants.

Remote Sensing: the gathering of data without actual contact with the materials or objects being studied. Some earth scientists define the term more narrowly, restricting "remote sensing" to the use of techniques involving radiation on the electromagnetic spectrum. The latter category includes visible, infrared, and ultraviolet light as well as lower-‐frequency signals in the microwave range of the spectrum.

Geographic Information Systems (GIS): Computer storage and analysis of maps and other geographic information; one use of GIS is a low‐energy precision application of irrigation water

Deforestation: The temporary or permanent clearance of large expanses of forests for agriculture or other uses

Gigaton (GT): A unit of explosive force equal to that of one billion (10⁹) tons of dynamite (TNT).

Output (to an ecosystem): Something that exits out of an ecosystem, most likely through the atmosphere (as a gas) or through stream water.

Sink (reservoir): is nutrient storage and may be different for each nutrient or they may be common depending on the nutrient.

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