1. Cycles of Matter

2. Cycles of Matter: Why? Because we have a fixed amount of STUFF (matter) on this planet, and no new stuff is being added from the universe Because we have a fixed amount of STUFF (matter) on this planet, and no new stuff is being added from the universe It must be cycled around and around. It must be cycled around and around.

3. Nitrogen Cycle – Why do we need nitrogen? In proteins (the building blocks of cells) No nitrogen? No proteins No cells No life

4. Nitrogen Cycle ~79% of air is made up of nitrogen We can’t use this form Must be “fixed” into solid form

5. Nitrogen Cycle The process of converting nitrogen from the gaseous form, N 2, into a solid form that’s usable for our bodies is called NITROGEN FIXATION

6. Nitrogen Fixation It takes a lot of energy to change nitrogen from its very stable form in the air, N 2 to a form our bodies can use. There are 3 ways nitrogen can be fixed: 1.Lightning 2.Nitrogen fixing bacteria 3.factories

7. Nitrogen Fixation - lightning 1.The high energy from lightning breaks some nitrogen molecules apart, allowing them to bond with oxygen in the air. 2.Then rain carries these new compounds down to the soil.

8. Nitrogen fixation - bacteria Nitrogen diffuses into soil, Nitrogen diffuses into soil, Special species of bacteria in the ground fix the nitrogen into ammonia and other nitrogen compounds Special species of bacteria in the ground fix the nitrogen into ammonia and other nitrogen compounds Two types of nitrogen-fixing bacteria Two types of nitrogen-fixing bacteria 1. free living bacteria 2.Bacteria that live in nodules of certain plants’ roots in a ______________ relationship Symbiotic mutualism Symbiotic mutualism

9. Nitrogen fixation - bacteria Plants that contain nitrogen-fixing bacteria in their root nodules: Alfalfa, legumes, clover & soy Farmers sometimes rotate these crops in just to add more nitrogen to their soil

10. Nitrogen Fixation - factories Humans have learned how to take gaseous nitrogen, N 2, and fix it into compounds to make fertilizer This takes huge amounts of energy

11. Nitrogen Cycle - Usage Once the nitrogen is fixed in one of the three ways, it can be used by plants

12. Nitrogen Cycle - Usage Finally, heterotrophs get the nitrogen by eating the plants or other animals that ate the plants.

13. Nitrogen Cycle – Back to Air When organisms die, decomposers get the last of their stored energy, and return their elements back to the soil. Some decomposing archaea break down the nitrogen compounds and release them back to their gaseous form, N 2. denitrification This process of breaking down nitrogen compounds and releasing them back as air is called denitrification.

14. Nitrogen cycle web site nitrogen cycle animation

15. Carbon (C) and Oxygen (O) cycles photosynthesis Plants do photosynthesis What do plants use for this? Water (H 2 O) and Carbon Dioxide (CO 2 ) Water (H 2 O) and Carbon Dioxide (CO 2 ) What do plants produce using photosynthesis? Glucose, a sugar (C 6 H 12 O 6 ) and oxygen (O 2 ), a waste product for plants

16. Carbon (C) and Oxygen (O) cycles All living things do cellular respiration to get… ENERGY What do plants and animals use for cellular respiration? Oxygen (O 2 ) and glucose (C 6 H 12 O 6 ) – exactly the products of photosynthesis!

17. Carbon (C) and Oxygen (O) cycles And cellular respiration produces what photosynthesis needs: carbon dioxide and water. And cellular respiration produces what photosynthesis needs: carbon dioxide and water. So the carbon and oxygen cycle around through cellular respiration and photosynthesis So the carbon and oxygen cycle around through cellular respiration and photosynthesis

18. Carbon (C) and Oxygen (O) cycles When organisms die, their bodies still contain the substances they had when they were alive. These get cycled back into the ground by … decomposers. When organisms die, the energy left over in their bodies is still stored in the carbohydrate compounds in their tissues. Organisms that died long ago and were buried under layers of sediments have been pressurized for many years and converted into … Fossil fuels

19. Fossil fuels come in the form of gasoline, oil, & coal. Fossil fuels come in the form of gasoline, oil, & coal. When we burn these fuels, this releases the carbon dioxide back into the air, just like breathing out does from cellular respiration. When we burn these fuels, this releases the carbon dioxide back into the air, just like breathing out does from cellular respiration. The process of powering a car with fossil fuels is the same as powering our bodies with fuel from plants – both produce carbon dioxide. The process of powering a car with fossil fuels is the same as powering our bodies with fuel from plants – both produce carbon dioxide. All the energy originally came from… All the energy originally came from… the sun. the sun.