1. Bell Ringer In nature, matter is constantly being recycled. What would happen if matter could not be recycled? Write a paragraph-length answer.

2. HOW IS MATTER RECYCLED? Cycles of Matter

3. Recall from the last unit that energy only goes in one direction – from producer to consumer. Unlike energy, matter is constantly recycled. This is because of the Law of Conservation of Mass.

4. Cycles of Matter Think about what happens in a food web. Producers are consumed by primary consumers. Those animals are eventually consumed by other animals. Eventually, all living organisms release waste, and all living organisms die and decompose. These processes release matter back into the world.

5. The Water Cycle All living organisms require water to survive. Water is constantly being recycled, so that all organisms can meet their water requirements. What would happen with no water cycle?

6. The Water Cycle Evaporation is the process of where liquid water becomes water vapor. Condensation is the opposite process. Water vapor becomes liquid water. Transpiration is the process where water evaporates from the leaves of plants.

7. The Water Cycle The water cycle is important because it is the reason we have precipitation and freshwater. Ocean water evaporates, forms clouds, and condenses into precipitation. Runoff becomes freshwater, groundwater or returns to the ocean.

8. The Water Cycle

9. The Carbon Cycle Carbon is one of the most important elements in our body. It is an important part of our biomolecules. Carbon is also being recycled, which results in carbon being moved from CO 2 to carbon compounds, and back again.

10. The Carbon Cycle CO 2 is released into the atmosphere by:  Respiration  Burning of fossil fuels  Wildfires/Volcanic activity Photosynthesis removes CO 2 from the atmosphere.

11. The Carbon Cycle CO 2 in the atmosphere and in the ocean is constantly being exchanged. Both photosynthesis and respiration occur underwater. Decomposing organisms become organic matter, and possibly fossil fuels.

12. The Carbon Cycle People and other animals breathe in oxygen, and breathe out carbon dioxide. As plants use carbon dioxide for photosynthesis, they create carbohydrates. Other organisms use carbon for other molecules, like calcium carbonate.

13. The Carbon Cycle

14. Exit Ticket 1. Why must matter constantly be recycled? 2. What do we call organisms that break down dead matter into smaller particles? 3. The process of converting water vapor to liquid water is _________. 4. Water evaporates from the leaves of plants in _________. 5. Photosynthesis removes ________ from the atmosphere. 6. Fossil fuels are formed from ________.

15. The Nitrogen Cycle The nitrogen cycle is important because nitrogen is the key component in amino acids, which make up our proteins. Nitrogen is a huge part of our planet, and takes various forms: nitrogen gas, ammonia, nitrites and nitrates.

16. The Nitrogen Cycle Nitrogen gas (N 2 ) is the most abundant form of nitrogen on the planet, but very few organisms can use it. It’s also the most abundant gas. Only certain bacteria, known as nitrogen fixers, can use nitrogen gas. They convert it into ammonia (NH 3 ). Nitrogen fixers are found in the soil, and on the roots of legumes.

17. The Nitrogen Cycle Other bacteria can then convert the ammonia (NH 3 ) into nitrites (NO 2 ‾ ) and nitrates (NO 3 ‾ ). Nitrites and nitrates are used by producers to make proteins. Consumers then get those proteins through consumption.

18. The Nitrogen Cycle Organisms also add nitrogen to the soil when they die. Decomposers, such as fungi, break dead organisms down.  Remember primary succession? Finally, some soil bacteria can convert nitrates into nitrogen gas via denitrification.

19. The Nitrogen Cycle The nitrogen cycle is critical for converting nitrogen gas to usable nitrogen compounds. Fixer bacteria synthesize nitrates and nitrates, which are absorbed by plants. Humans and other animals consume plants and other animals to get the nitrogen compounds.

20. The Nitrogen Cycle

21. The Phosphorus Cycle The phosphorus cycle provides us with phosphorus, a key component of DNA and RNA. It is rather uncommon, though. It does NOT become airborne at any point.

22. The Phosphorus Cycle Most phosphorus in nature is locked in rock and soil.  This includes ocean sediment. Eventually, these rocks are broken down, and the soil washed away.

23. The Phosphorus Cycle This phosphorus is usually washed into the rivers and oceans. However, some phosphorus is absorbed by plants. Plants use this phosphorus to make organic molecules.

24. The Phosphorus Cycle Once again, humans and other animals eat the plants to get phosphorus… …or they eat other animals to get phosphorus. What other cycle does this remind you of?

25. The Phosphorus Cycle

26. Exit Ticket 1. Most nitrogen on Earth is found in the form of ____________. 2. Can we use pure nitrogen gas as a nutrient? 3. What do we call bacteria that convert nitrogen gas to nitrites and nitrates? 4. ___________ also add nitrogen to the soil as they break down dead organisms. 5. Where is most phosphorus found in nature? 6. How do we obtain nitrogen and phosphorus from the environment?