The Chemical The Chemical Cycles Cycles

Unlike energy, matter can be Unlike energy, matter can be recycled. The Water, Carbon, and recycled. The Water, Carbon, and Nitrogen Cycles are the three main Nitrogen Cycles are the three main ways matter is recycled in the ways matter is recycled in the environment. environment.

The Water Cycle The Water Cycle

More than ninety percent of the More than ninety percent of the Earth's water is locked beneath its Earth's water is locked beneath its surface either in crystal rocks or surface either in crystal rocks or deep in the interior and does not deep in the interior and does not take part in the water cycle. A large take part in the water cycle. A large portion of the water that does portion of the water that does participate in the water cycle comes participate in the water cycle comes from the Earth's oceans. from the Earth's oceans.

The Water CycleThe Water Cycle

The Water CycleThe Water Cycle

Step 1:  A large quantity of water Step 1:  A large quantity of water evaporatesevaporates from the surface of the from the surface of the ocean.ocean. Evaporation Evaporation is the is the conversion of liquid water to a conversion of liquid water to a gaseous form of water called water gaseous form of water called water vapor vapor

The Water CycleThe Water Cycle

Step 2: The water vapor then Step 2: The water vapor then condenses to form clouds. Most of condenses to form clouds. Most of this condensed water will then this condensed water will then precipitateprecipitate back into the ocean, but back into the ocean, but some will travel on and eventually some will travel on and eventually float over land. float over land. PrecipitatePrecipitate means means to condense from a vapor and fall as to condense from a vapor and fall as rain or snow.rain or snow.

The Water CycleThe Water Cycle

Step 3:  The condensed water (clouds) that Step 3:  The condensed water (clouds) that floats over land picks up more water vapor floats over land picks up more water vapor from evaporation and from evaporation and transpirationtranspiration. . TranspirationTranspiration is the evaporation of water is the evaporation of water from the leaves of plants.from the leaves of plants.

Step 4:  The accumulated water vapor will Step 4:  The accumulated water vapor will then fall to the ground as rain.then fall to the ground as rain.

Step 5:  The rain water makes its way back Step 5:  The rain water makes its way back to the ocean through streams and rivers to the ocean through streams and rivers and starts the water cycle over again.and starts the water cycle over again.

The Carbon CycleThe Carbon Cycle

The Carbon Cycle describes the flow The Carbon Cycle describes the flow of carbon between living organisms of carbon between living organisms and the non-living environment. and the non-living environment.

Carbon cycles through the Carbon cycles through the environment in the form of a gas, environment in the form of a gas, carbon dioxide (COcarbon dioxide (CO22). The ). The atmosphere of Earth contains .04 atmosphere of Earth contains .04 percent COpercent CO22. .

The Carbon CycleThe Carbon Cycle

Living organisms provide two Living organisms provide two important steps in the carbon cycle:important steps in the carbon cycle:

Plants absorb COPlants absorb CO22 from the from the atmosphere to use during atmosphere to use during photosynthesisphotosynthesis..

Other organisms release COOther organisms release CO22 into into the air during the air during respirationrespiration. .

In addition, there are several important non-In addition, there are several important non-organic storage areas of carbon in the organic storage areas of carbon in the environment:environment:

A large portion of the Carbon on the Earth is A large portion of the Carbon on the Earth is stored in rocks.stored in rocks.

The Earth's oceans hold a large amount of COThe Earth's oceans hold a large amount of CO2 2

because it easily dissolves in water. because it easily dissolves in water. Coal, oil, and limestone store carbon that once Coal, oil, and limestone store carbon that once

formed ancient organisms. Burning fossil fuels, formed ancient organisms. Burning fossil fuels, like coal and oil, will release COlike coal and oil, will release CO22 into the into the atmosphere.atmosphere.

The Nitrogen CycleThe Nitrogen Cycle

OrganismsOrganisms require nitrogen to require nitrogen to produce amino acids. Nitrogen makes produce amino acids. Nitrogen makes up seventy-eight percent of the up seventy-eight percent of the atmosphere, but most organisms can atmosphere, but most organisms can not use this form of nitrogen, and must not use this form of nitrogen, and must have the fixed form. The nitrogen cycle have the fixed form. The nitrogen cycle produces the fixed form of nitrogen produces the fixed form of nitrogen these organisms need.these organisms need.

The Nitrogen CycleThe Nitrogen Cycle

The Nitrogen CycleThe Nitrogen CycleStepsSteps

Step 1:  A special type of bacteria Step 1:  A special type of bacteria called nitrogen fixing bacteria take called nitrogen fixing bacteria take in atmospheric nitrogen and produce in atmospheric nitrogen and produce ammoniaammonia (NH3). (NH3).

Step 2:  Other bacteria use this Step 2:  Other bacteria use this ammonia to produce nitrates and ammonia to produce nitrates and nitrites, which are nitrogen and nitrites, which are nitrogen and oxygen containing compounds. oxygen containing compounds.

Step 3:  The nitrates and nitrites are Step 3:  The nitrates and nitrites are used by plants to make amino acids used by plants to make amino acids which are then used to make plant which are then used to make plant proteins.proteins.

Step 4:  Plants are consumed by Step 4:  Plants are consumed by other organisms which use the plant other organisms which use the plant amino acids to make their own. amino acids to make their own.

Step 5:  Decomposers convert the Step 5:  Decomposers convert the nitrogen found in other organisms nitrogen found in other organisms into ammonia and return it to the into ammonia and return it to the soil. A few of these type of bacteria soil. A few of these type of bacteria return nitrogen to the atmosphere return nitrogen to the atmosphere by a process called denitrification, by a process called denitrification, however this amount is small.however this amount is small.