Cycles of Matter

Recycling Matter

• Energy cannot be recycled but decreases as it is passed through the ecosystem.

• Matter is continually recycled in a system.

• Cycles of Matter– Water– Carbon & Oxygen– Nitrogen

Water Cycle

• Continuous process by which water moves from Earth’s surface to the atmosphere and back.

• Includes– Evaporation (Liquid Gas

Vapor)– Condensation (Gas Vapor

Liquid)– Precipitation (Liquid falls

from clouds)

Carbon & Oxygen Cycle

• Photosynthesis– Producers use carbon

dioxide and sunlight to produce glucose (sugar).

– Uses carbon dioxide, releases oxygen

• Respiration– Consumers break down

glucose to release energy and carbon dioxide

– Uses oxygen, releases carbon dioxide

6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2

6O2 + C6H12O6 -->  6H2O + 6CO2 + energy

Carbon & Oxygen Cycle

Plant uses carbondioxide to make

sugar molecules.

Animal releasescarbon dioxide

into the air.

Animal eats sugar molecule.

Plant takes in carbon dioxide.

Carbon & Oxygen Cycle

Plant uses carbondioxide to make

sugar molecules.

Animal releasescarbon dioxide

into the air.

Animal eats sugar molecule.

Plant takes in carbon dioxide.

Carbon & Oxygen Cycle

Plant uses carbondioxide to make

sugar molecules.

Animal releasescarbon dioxide

into the air.

Animal eats sugar molecule.

Plant takes in carbon dioxide.

Carbon & Oxygen Cycle

Plant uses carbondioxide to make

sugar molecules.

Animal releasescarbon dioxide

into the air.

Animal eats sugar molecule.

Plant takes in carbon dioxide.

CO2 inAtmosphere

CO2 in Ocean

Section 3-3

Figure 3-13 The Carbon CycleCarbon & Oxygen Cycle

Nitrogen Cycle

• Nitrogen Gas (Free nitrogen)– Most common form of nitrogen.– Cannot be used by organisms like us that need nitrogen– Must be converted into usable form.

• Nitrogen Fixation– Process of changing nitrogen gas from the air into nitrogen

compounds plants can use.– Performed by bacteria (some live in roots of plants—called

nodules)• Fixed Nitrogen

– Used by organisms to build proteins• Decomposers

– Break down proteins into nitrogen compounds in soil.– Bacteria further break down nitrogen into nitrogen gas

Nitrogen Cycle

Nitrogen Cycle

Nitrogen Cycle

Nitrogen Cycle

Nitrogen Cycle

Nodules

N2 in Atmosphere

NH3

NO3-

and NO2-

Section 3-3

Figure 3-14 The Nitrogen CycleNitrogen Cycle

Summary Questions

• Name and define the three major processes that occur during the water cycle.

• Explain the role of plants in the carbon cycle.

• Why is nitrogen fixation a necessary part of the nitrogen cycle?

• Where do nitrogen-fixing bacteria live?

• Explain how the movement of matter through an ecosystem is different from the movement of energy through an ecosystem.