2.2 Cycles of Matter

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

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

Condensation step The process by which gas molecules lose energy and change into a liquid.

Precipitation step As water vapor condenses, the drops of water in the cloud grow larger and heavy. The heavy drops fall as rain, snow, sleet, or hail.

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 ( green plants ) to make sugars during photosynthesis. The producers then give off oxygen.

Carbon Cycle STEP 2 Consumers eat the plants, passing the carbon compounds along in the food chain. Most of the carbon ( food is fuel burned to live ) is exhaled as carbon dioxide, through the process of respiration. The producers and consumers then eventually die.

Carbon Cycle STEP 3 The dead producers and consumers are broken down by the decomposers. The carbon that was in the dead organisms is then returned to the atmosphere as carbon dioxide.

Oxygen Cycle Producers release oxygen as a by-product of photosynthesis. Most consumer 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. Mutualism = Bacteria living in Nodules on plant roots Legumes Plants with nodules – Clover – Beans – Peas – Alfalfa – Peanuts

Nitrogen Cycle