2.2

Cycles of Matter

Water cycle

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

Evaporation

• Process by which molecules of liquid water absorb energy and change into a gas.

Condensation

• The process by which a gas changes to a liquid.

Precipitation

• As more water condenses, the drops of water in a cloud grow large and fall to the ground as rain.

Water Cycle

The Carbon and Oxygen cycles

• Producers , consumers and decomposers each play a role in the carbon cycle and the oxygen cycle.

Carbon Cycle STEP 1

• Carbon dioxide is absorbed by producers to make sugars during photosynthesis. These producers then put off oxygen.

Carbon Cycle STEP 2

• Consumers feed on the plants. Thus passing the carbon compounds along the food chain. Most of the carbon these consumers consume however is exhaled as carbon dioxide. This is through the process of respiration. The producers and consumers then eventually die.

Carbon Cycle STEP 3

• The dead producers and consumers are eaten by decomposers. The carbon that was in their bodies is then returned to the atmosphere as carbon dioxide.

Oxygen Cycle

• Producers release oxygen as a result of photosynthesis.

• Most organisms take in oxygen from the air and use it to live.

Human impact

• Humans affect the levels of carbon and oxygen in the atmosphere.

• When we burn fuels like wood and gasoline carbon dioxide is released into the air.

The Carbon and Oxygen cycles

Nitrogen Cycle

• Nitrogen moves from the air to the soil, into living things and back into the air.

Nitrogen Fixation

• The process of changing free nitrogen into a usable form of nitrogen.

• Nodules• Legumes – Clover– Beans– Peas– Alfalfa– Peanuts

Nitrogen Cycle