The Carbon and Nitrogen Cycle How does carbon and nitrogen cycle through the biosphere? How does nitrogen and carbon cycle through the atmosphere? This Photo by Unknown Author is licensed under CC BY-NC-ND

What are some of the components, living and non- living of this ecosystem? How might some of the conditions in this ecosystem fall out of balance? How might such changes affect the ecosystem? This Photo by Unknown Author is licensed under CC BY-SA Ecosystems

Carbon in the atmosphere and biosphere Carbon moves between living and non-living things on Earth These movements make up the carbon cycle One part of the carbon cycle centers on photosynthesis Carbon exits Earth’s atmosphere primarily with molecules of carbon dioxide (CO2) This Photo by Unknown Author is licensed under CC BY-SA

Photosynthesis During the Calvin Cycle of photosynthesis, plants use the carbon to make organic compounds called carbohydrates One of the most important carbohydrates is glucose, a sugar that plants use for food Plants store glucose for later use in the form of starch, another carbohydrate This Photo by Unknown Author is licensed under CC BY-NC

Consumers Consumers are organisms that consume carbohydrates produced by plants Consumers use the energy held in the bonds of these molecules to fuel their cellular activities, called cellular respiration One of the waste products of cellular respiration is CO2 In this way, carbon cycles continuously between the atmosphere as CO2 and the biosphere as carbohydrates This Photo by Unknown Author is licensed under CC BY-ND

Biomass Biomass is the living, or recently living matter in an ecosystem Carbon is also returned to the environment through decomposition The bodies of organisms are primarily made of carbon Decomposers break down the bodies into their component elements, and carbon moves into the ground This Photo by Unknown Author is licensed under CC BY-SA

Carbon moves from the biomass into the ground where it remains for millions of years Heat and pressure from Earth’s interior transformed buried plants and animals from the Carboniferous period (300-350 mya) into coal, petroleum, and natural gas When we burn fossil fuels, it releases carbon back into the atmosphere where it can be used again by plants This Photo by Unknown Author is licensed under CC BY-SA Fossil fuels

Global warming controversy Fact: burning fossil fuels releases carbon into the atmosphere Fact: humans are removing producers from Earth’s surface Fact: research is being done everywhere to reduce carbon emissions Opinion: Reducing carbon emissions is a good thing Realistically, can everyone drive a Tesla? Is it practical for a family of 5 or more to ride around in a Prius? This Photo by Unknown Author is licensed under CC BY-SA-NC Global warming controversy

Source Checklist Form your own opinion Anyone can publish to the internet Study both sides of a controversial topic so you can have an intelligent conversation Know why you choose, not just that you do. This Photo by Unknown Author is licensed under CC BY-SA-NC

Day 2 -The Nitrogen Cycle Both plants and animals require nitrogen to survive It is a key element in DNA and RNA, and amino acids which are used to make proteins Approximately 78% of Earth’s atmosphere is nitrogen (N2) Most living things cannot use nitrogen in this form This Photo by Unknown Author is licensed under CC BY-SA-NC

Nitrogen Fixing Bacteria This Photo by Unknown Author is licensed under CC BY-SA

Nitrogen Fixing Many legumes – peas, soybeans, peanuts, and alfalfa coexist with a bacteria called Rhizobia They live in the soil on the roots of the plant, and take nitrogen and fix in into NH3 Other bacteria change the ammonia into nitrites and nitrates, in a process called nitrification This Photo by Unknown Author is licensed under CC BY-SA

Assimilation Plants absorb the nitrogen compounds from the soil through their roots and use them to synthesize amino acids, called assimilation As consumers eat plants, nitrogen gas passes up the food chain for other organisms to use Some bacteria turn nitrates into nitrogen gas, called denitrification, and release it back into the atmosphere This Photo by Unknown Author is licensed under CC BY-SA

The decomposition of organic matter is also a crucial part of the nitrogen cycle When organisms die, nitrogen compounds held in their bodies are broken down by detritivores and are returned to the soil as nitrates and nitrites Bacteria in the soil can convert these compounds into ammonia The plants can then reabsorb these compounds This Photo by Unknown Author is licensed under CC BY-SA Detritivores

Lightning Does lightning add nitrogen to the soil Answers.com – not a good source Nitrogen fixation by lightning – Kimball’s biology pages Nova: Earth from Space| Lightning Produces Nitrates This Photo by Unknown Author is licensed under CC BY-SA Lightning

Disruptions in the cycles Compost: a mixture of decaying organic matter, air, and water that may be used to fertilize soil The total amount of carbon actively moving through the carbon cycle decreases when people bury organic materials in landfills rather that allow them to decompose naturally outdoors Ideally, fallen leaves and discarded foods should be used for compost, allowing nutrients in the decomposing biomass to return to the ecosystem This Photo by Unknown Author is licensed under CC BY-ND

In the last 150 years, there has been a dramatic increase in the burning of coal, oil and natural gas for factories, cars, airplanes, heat, and other technologies Not only does this deplete the Earth of its natural fossil fuel resources, it creates an imbalance in the carbon cycle There are many agencies, and organizations around the world working to reduce the carbon emissions from these sources This Photo by Unknown Author is licensed under CC BY-NC-ND Fossil Fuel Burning

Fertilizers Overusing nitrogen-based fertilizers in agriculture also disturbs the nitrogen cycle The availability of nitrogen can be a limiting factor to the growth of crops Farmers use fertilizers with high concentrations of nitrogen and other nutrients They help with farming, but get carried away by rainwater Causes buildup in estuaries, lakes, and streams, called eutrophication Algae thrives on the excess nitrogen and reproduce uncontrollably As they die, the decomposers will use up the oxygen, choking out other organisms in the water This Photo by Unknown Author is licensed under CC BY-SA