Cycles in Nature

 Where matter is recycled but never replenished. –It is never lost.  Sunlight= primary source of energy

Carbon Cycle  All life on Earth is based on carbon molecules.  Atoms of carbon form the framework for protein, carbohydrates, and fats.  Carbon is the MOLECULE of Life.  Begins with an autotroph (uses sunlight to produce food)

Photosynthesis The process in which plants change the energy in sunlight to kinds of energy that can be stored for later use.

 Autotrophs convert carbon dioxide into energy-rich carbon molecules.  Heterotrophs feed on autotrophs for food and energy.  When autotrophs and heterotrophs use the carbon containing molecules, carbon is released and returns to the atmosphere.

Sources of Carbon:  Soil, leaves, roots, tied up in forests, in oil or coal, and in animal fossils. Dinosaur Carbon Reading D-1 Dinosaur Breath Lab Carbon Cycle WS Carbon Cycle HW

Photosynthesis vs. Respiration  Photosynthesis –Carbon dioxide is used  Respiration –Carbon dioxide is produced

Root Meaning of Words: “Photo”= light “Synthesis”= to put together

What is Photosynthesis? The broad surface area of the leaf absorbs sunlight to be used as energy Carbon dioxide is taken in from the air.

 Green plants manufacture their own food by the process known as photosynthesis.  Plants take in nutrients and make their own food : Animals depend on plants for food.

What do plants need to manufacture food through photosynthesis?  Water  Light  Chlorophyll  Carbon Dioxide (CO2)

Formula for Photosynthesis 6CO 2 + 6H 2 OC 6 H 12 O 6 + 6O 2 Light Carbon Dioxide + Water Glucose + Oxygen Photosynthesis Activity Photosynthesis Web quest HW

Respiration The process that involves oxygen and breaks down food molecules to release energy. Formula: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O Glucose + Oxygen Carbon Dioxide + Water

Review 1. What do autotrophs convert carbon dioxide into? 2. What do heterotrophs feed on autotrophs for? 3. How do autotrophs and heterotrophs contribute to the carbon cycle? 4. Name 4 sources of carbon 5. Describe the difference between photosynthesis and respiration 6. Describe the process of photosynthesis (equation)

Nitrogen Cycle  Air is 78% Nitrogen  Plants, however, cannot use nitrogen in the air.  They use nitrogen in the soil that has been converted into a usable form.  Plants use nitrogen to make important proteins.

 Herbivores eat plants and convert nitrogen containing plants into nitrogen- containing animals.  Once eaten it is converted into animal waste containing nitrogen compounds.  Urine returns nitrogen into the water or soil and eventually into the atmosphere.

 When animals die or decay nitrogen is also returned  Plants reuse nitrogen.  Soil bacteria act on molecules and put nitrogen back into the air.

Nitrogen Activities  Farming Nitrogen Lab  Nitrogen Cycle WS  Cycles & Processes Poster Project

Review 1. Name the 4 components that plants need to manufacture food through photosynthesis. 2. Write out the formula for photosynthesis. 3. What is respiration. 4. Write the formula for respiration. 5. What percentage of nitrogen is in the air 6. How do plants use nitrogen? 7. Describe how herbivores contribute to the nitrogen cycle.