1. Biogeochemical Cycles Water Carbon Nitrogen

2. 4 ATOMS make up 95% of the body in most organisms CARBON HYDROGEN OXYGEN NITROGEN The same molecules are passed around again and again within the biosphere in BIOGEOCHEMICAL CYCLES

3. WATER CYCLE = ___________________ HYDROLOGIC CYCLE

4. WHY IS WATER IMPORTANT? Makes up 60-70% of your body Oxygen and Hydrogen are found in all the building blocks of cells carbohydrates, proteins, nucleic acids, lipids Hydrogen in H 2 O supplies protons (H + ) & electrons For photosynthesis.

5. WATER CYCLE evaporation condensation

6. The evaporation of water from the surface of plant leaves = TRANSPIRATION The return of water to the surface in the form of rain, snow, sleet, hail, etc. = PRECIPITATION

7. WATER CYCLE

8. CARBON CYCLE CO 2 in atmosphere CO 2 in ocean

9. 4 main CARBON reservoirs in BIOSPHERE CO 2 in atmosphere CO 2 in Ocean 1.In oceans as CO 2 gas 2.In the atmosphere as dissolved CO 2 gas 3.On land in organisms, rocks, soil 4. Underground as coal & petroleum (fossil fuels) and calcium carbonate in rocks

10. Where does CO 2 in atmosphere come from? CO 2 in atmosphere CO 2 in Ocean 1.Volcanic activity 2.Human activity (burning fossil fuel) 3.Cellular respiration 4.Decomposition of dead organisms

11. WHY IS CARBON IMPORTANT? Found in all the building blocks of cells: carbohydrates, proteins, nucleic acids, lipids

12. WHY IS CARBON IMPORTANT? Carbon in CO 2 provides the atoms for glucose production during photosynthesis the fuel that all living things depend on.

13. N 2 in Atmosphere NH 3 NO 3 - and NO 2 - Section 3-3 NITROGEN CYCLE

14. WHY IS NITROGEN IMPORTANT? Nitrogen bases make DNA and RNA Adenine (nitrogen base) is used in ATP. Makes AMINO part of amino acids in (proteins)

15. 79% of the atmosphere is made up of NITROGEN gas (N 2 ) BUT we Can’t use the nitrogen gas we breathe! The bond in N 2 gas is so strong it can only be broken by Lighting, volcanic activity, and a few special bacteria

16. Bacteria that live in the soil and in symbiotic relationships with plants called legumes, take nitrogen from the atmosphere and turn it into Ammonia, a form that is usable by plants. THIS PROCESS IS CALLED NITROGEN FIXATION

17. Other bacteria in the soil convert ammonia into which plants can also use. The nitrogen we need for proteins, ATP, and nucleic acids comes from the Food we eat we breathe! NITRATES (NO 3 - ) Not the air and NITRITES (NO 2 - )

18. N 2 in Atmosphere NH 3 NO 3 - and NO 2 - Section 3-3 NITROGEN CYCLE BIOLOGY; Miller and Levine; Prentice Hall; 2006

19. Bacteria that live in the soil also carry out the reverse process Nitrates/ Nitrates → Nitrogen gas. THIS PROCESS IS CALLED DENITRIFICATION