Cycles of Matter

Recycling in the biosphereA. Remember:

1. Energy is NOT recycled

2. Matter IS recycled

B. Biological systems do not use up matter; they transform it.

1. In other words, the same molecules are passed around again and again within the biosphere.

a. We are breathing the same oxygen atoms that dinosaurs might have!

Biogeochemical CyclesA. Recycle matter within the biosphere

B. Biological, geological, and chemical aspects of the biosphere are connected and continually recycled, or passed, from one organism to another and from one part of the biosphere to another

C. The two most important biogeochemical cycles are: the water cycle and nutrient cycles

The Water Cycle

A. All living things require water to survive

B. Water moves between bodies of water, atmosphere, and land

Water Cycle Terms

A. During the day, the sun heats the environment, which causes water molecules to enter the atmosphere through evaporation or transpiration

1. Evaporation = Water changes from liquid to atmospheric gas

2. Transpiration = Water evaporates from the leaves of plants

Water Cycle Terms (Continued)

B. The warm, moist air filled with water vapors becomes cool as it rises.

1. This leads to condensation = water vapor (gas) turns into liquid water, forming clouds

C. Precipitation = the water droplets within the clouds become large enough to fall to Earth in the form of rain, snow, sleet, or hail

Water Cycle Terms (Cont.)D. Surface Runoff

1. Most of the precipitation that falls to the Earth runs along the surface of the ground until it enters a body of water

2. Precipitation can also seep into the soil and enter plants through their roots

3. Once runoff enters a body of water or seeps into the ground, the water molecules will evaporate or transpire again

CondensationPrecipitation

Evaporation TranspirationRun off

Seepage

Root uptake

Nutrient Cycles

A. Nutrients = all chemical substances that an organism needs to sustain life

1. Help organisms build tissues and carry out essential life functions

B. Like water, nutrients are passed between organisms and the environment through biogeochemical cycles.

Nutrient Cycles (Continued)

C. Nutrients are in short supply for most ecosystems

1. Recycling nutrients becomes essential for ecosystems to function

a. Keeps a constant flow

b. Prevents chemicals from reaching toxic levels of concentration

D. Three most important nutrient cycles are:1. Carbon, Nitrogen, and Phosphorus cycles

The Carbon CycleA. Carbon is the key ingredient of living

tissue

B. Carbon is found in:

organisms,

oceans, air, and certain

types of rocks

The Carbon Cycle (Cont.)

C. CO2 (Carbon Dioxide)

1. Makes up atmosphere

2. Released into atmosphere by organisms breathing, volcanic activity, burning fossil fuels, and vegetation

3. Releases into ground through decomposition of organic matter

4. Taken in by plants in photosynthesis

The Carbon Cycle (Cont.)D. There are four main processes involved in

the carbon cycle:1. Biological = photosynthesis,

respiration, and decomposition2. Geochemical = erosion and volcanic

activity3. Mixed Biogeochemical = burial and

decomposition4. Human Activities = mining, cutting &

burning forest, burning fossil fuels

E. Steps of The Carbon Cycle1. Carbon enters the atmosphere from breathing

and combustion

2. Producers use carbon dioxide in photosynthesis.

These producers then release oxygen.

3. Animals inhale the oxygen and exhale carbon dioxide. Animals also feed on the plants. The animals and plants eventually die.

4. Decomposers eat the dead plants and animals. The carbon that was in animal and plants is then returned to the atmosphere as carbon dioxide.

CO2 in

atmosphere

CO2 in ocean

The Nitrogen CycleA. All organisms require nitrogen to make amino acids

(which are used to build proteins)

B. Nitrogen gas (N2) makes up 78% of Earth’s atmosphere

1. Not usable by most organisms

C. Nitrogen containing substances such as ammonia (NH3), nitrate ions (NO3-), and nitrite ions(NO2-) are found in waste from organisms and in dead and decaying organic matter

1. These are usable forms of nitrogen

D. Humans add nitrogen to the biosphere through nitrate (fertilizers)

The Nitrogen Cycle (Cont.)E. Only certain bacteria can use nitrogen gas directly

1. Found in soil and on roots of plants called legumes (beans, peas, peanuts, etc.)

2. They convert it to ammonia through nitrogen fixation

F. Other bacteria convert ammonia into nitrates & nitrites1. Producers use it to make proteins, and consumers eat

producers and reuse nitrogen to make proteins

G. When organisms die, decomposers return nitrogen to soil as ammonia1. Ammonia is taken up by producers (again)

H. Other soil bacteria convert nitrates into nitrogen gas through denitrification, which releases nitrogen back into the atmosphere

Nitrogen CycleN2 in atmosphere

NH3

ammonia

NO3- & NO2

-

Nitrate & nitrite

1.Organic wastes(from plants and animals) add nitrogen to the soil. 2.Bacteria in the soil convert the nitrogen into forms plants can use. 3.Plants use nitrogen in the soil to grow, develop, and produce seeds. 4.Plants are eaten by animals and people. The organic waste (which contains nitrogen) is returned to the soil again.

Simplified Nitrogen

Cycle

The Phosphorus CycleA. Phosphorus is essential to living organisms

1. Forms part of life-sustaining molecules such as DNA and RNA

B. Phosphorus is not common in the biosphere1. Does not enter the atmosphere2. Exists on land in rock and soil minerals, and in

ocean sedimentsa. Phosphate is released as rocks and sediments

gradually wear downb. On land, phosphate washes into rivers and

streams, where it dissolves and eventually makes its way to oceans

The Phosphorus Cycle (cont.)C. Runoff/Collection:

1. Erosion transfers phosphorus to water and soil; sediments and rocks that accumulate on ocean floors return to the surface as a result of uplifting by geological processes

D. Absorption/Consumption1. Plants absorb inorganic phosphate from soils;

animals obtain organic phosphorus when they eat plants and other animals

E. Decomposition/Release 1. Plants and animals release phosphorus when they

decompose; animals excrete phosphorus in their waste products