Bell Ringer What substances are need for photosynthesis and what are produced during photosynthesis? You have 5 minutes to get a piece of paper and write down the answer.

Chapter 2 Ecosystems and Biomes Section 2 Cycles of Matter Notes 2-2

Recycling Matter  Matter is recycled in ecosystems Like cans are recycled Ex: water, carbon, oxygen, nitrogen  Energy is not recycled in ecosystems Sunlight or gasoline must be constantly supplied Enters at the producers and moves through the consumers until it is gone

Water Cycle  Water is necessary for all life as we know it What scientists are looking for on other planets to find other life  Water Cycle: continuous process by which water moves form Earth’s surface to the atmosphere and back

Water Cycle  Evaporation: Process in which molecules of liquid water absorb energy and change into the gas state Liquid water to water vapor Plants lose water from their leaves = transpiration Animals lose water when they exhale

Water Cycle  Condensation: Process by which a gas changes into a liquid When water cools, the vapor changes into a liquid Water droplets can form around a small piece of dust and form a cloud or rain drop

Water Cycle  Precipitation: When water falls back to the earth  Form of rain, snow, sleet or hail Precipitation becomes groundwater when it reaches the soil or it can become part of a river or ocean

Carbon and Oxygen Cycle  Carbon is the building block of that matter that makes up all living things  Found in the atmosphere in the form of carbon dioxide  Producers take in carbon dioxide during photosynthesis

Carbon and Oxygen Cycle  Producers use carbon (from CO 2 ) to make carbon-containing molecules Like sugars and starches  Consumers use sugars and starches for energy Give off water and carbon dioxide as waste  Producers give off oxygen as waste  Consumers use oxygen in their life processes

Nitrogen Cycle  Atmosphere is 78% Nitrogen (N 2 )  However, most organisms can’t use nitrogen from the air Nitrogen gas is called “free” nitrogen Must be “fixed” or combined with other atoms to be used by most organisms

Nitrogen Cycle  Nitrogen Fixation: Process of changing free nitrogen gas into the usable form of nitrogen Most is done by nitrogen-fixing bacteria These bacteria are found in nodules on the roots of plants  Plants like: clover, beans, peas, alfalfa and peanuts

Nitrogen Cycle  Farmers use legumes (alfalfa) to build up the nitrogen compounds in the soil After planting other crops for a couple of years, farmers plant legumes to re- enrich the soil  Called crop rotation

Nitrogen Cycle  Nitrogen is used by organisms to build proteins and other substances  Decomposers break down these substances of dead matter They return it to the soil  Bacteria can also release free nitrogen back into the atmosphere

HOMEWORK Section Review Page 55 #1-5