Chapter 5 : Ecosystems and the Physical Environment

1. Chapter 5: Ecosystems and the Physical Environment

2. The Atmosphere http://mediatheek.thinkquest.nl/~ll125/en/atmos.htm

3. The Atmosphere

4. Hypothesis • Gaea= Greek “goddess of Earth” or “mother” Earth. 1970’s; This theory proposed global self-regulation.

5. Hypothesis Example: Earth’s temperature has remained stable due to organisms fixing CO2 into Calcium Carbonate CaCO3 of shells. Corals, Crustacea…

6. Planetary Temperature as aNegative Feedback loop? Example: A thermostat only turns on when the temperature drops below the desirable temp. Once it reaches the correct temperature the heat turns off.

7. Energy and Matter

8. Do Now: Biogeochemical cycles • Identify the five Biogeochemical cycles. • Identify some major reactions that occur for each. • Discuss their importance, be sure to include the interaction between biotic & abiotic factors.

9. Biogeochemical cycles • Interaction between biotic & abiotic. • Transpiration, decomposition, Photosynthesis and respiration • The recycling of materials to be used over & over again. • 5 examples are: 1. Phosphorus cycle 2. Nitrogen cycle 3. Hydrologic cycle 4. Carbon cycle 5. Sulfur cycle

10. Do Now: • Draw a simple carbon for your bioregion. Include all the relevant processes as well as the local / regional geographical features that are part of the cycle.

11. The Carbon-Cycle • Carbon, hydrogen, and oxygen are recycled through the environment by the processes of respiration and photosynthesis. • Carbon makes up0.038% of our atmosphere (CO2) • Oceanic Carbon • Carbonate (CO3 2− ) • Bicarbonate HCO3 − ) • Dissolved organics from decay • Sedimentary Rock • Limestone: Calcium carbonate CaCO3

12. The Carbon-Cycle • Atmospheric Carbon • 0.038% of our atmosphere carbon dioxide CO2 • Carbonic Acid (H2CO3) • Oceanic Carbon • Carbonate (CO3 2− ) • Bicarbonate (HCO3 − ) • Dissolved organics from decay • Sedimentary Rock • Limestone: AKA Calcium carbonate: (CaCO3)

13. The Carbon-Cycle • CO2 + H20 Carbonic Acid (H2CO3) (combines in rainwater) 2. H2CO3- HCO3 − and H+ (dissociates in soil) 3. H+ (acidic) breaks down feldspar Ca2+ 4. H2CO3- + Ca2+  CaCO3 (in runoff combines) forming 5. CaCO3 in runoff up taken and used by oceanic organisms 6. Organisms die, sedimentation occurs forming Limestone

14. Carbon Cycle

15. The Carbon-Cycle The Carbon cycle

16. The Carbon-Cycle C6H12O6 + 6O2 +6H2O 6CO2 + 12H2O + 36ATP’s 6CO2 + 12H2O + light C6H12O6 + 6O2 +6H2O

17. Remember Photosynthesis ??

18. Respiration • The transfer of stored energy in food molecules to a form usable by the organism. • Involves the exchange of gases between the organism and the environment.

19. Process • Through the process of respiration, the organism produces adenosine triphosphate (ATP) which will be used for energy.

20. Respiration • Respiration- is an organisms’ ability to create energy. (ATP) Respiration Aerobic Respiration Anaerobic Respiration Alcoholic Fermentation Lactic Acid Fermentation

21. 1. Cellular Respiration • Involves a series of enzyme-controlled reactions in which energy in food is broken down into energy that the organism can use (ATP)

22. a) When ATP is broken down, energy is released and ADP is formed ADP = adenosine diphosphate H2O + ATP  ADP + P + energy • This is the energy used by the body to carry out the functions of life

23. Types of Respiration • Aerobic Respiration -involves the use of oxygen 2. Anaerobic Respiration -oxygen is not used

24. Anaerobic Respiration • Also known as Fermentation • Does not require oxygen • Takes place in the cytoplasm of cell • Glucose is either broken down into lactic acid or alcohol and CO2 • As a result of anaerobic respiration, there is a net gain of 2 ATP’s

25. Equations for Anaerobic Respiration glucose  2 lactic acids + 2 ATP’s glucose  2 alcohol + 2 CO2 + 2 ATP’s • In each equation, enzymes are used and a net gain of 2 ATP’s are produced

26. Aerobic Respiration • Requires oxygen • Takes place in the mitochondria • When we say that glucose is oxidized, we say that it is broken down with the help of oxygen molecules http://www.biosci.ohio-state.edu/~dcp/bio113a/ch910comp.html

27. Summary • Anaerobic Respiration = 2 ATP’s • Aerobic Respiration = 36 ATP’s • Therefore, Aerobic respiration is more efficient than anaerobic respiration

28. The Carbon-Cycle

29. Glycolysis

35. Mitochondrion An oval membrane enclosed organelle in which most of the reactions of cellular respiration occur.

36. Aerobic Respiration (Net gain of ATP) • Glycolysis (2 ATP’s) • Krebs Cycle (2 ATP’s) • Electron Transport Chain (ETC) (32 ATP’s)

37. Nitrogen Cycle http://www.biology.ualberta.ca/facilities/multimedia/index.php?Page=280 • Nitrogen is needed by all living things because it is part of the structure of amino acids and proteins. • The Nitrogen cycle includes the following reactions nitrogen-fixation, nitrification, ammonification, and denitrification. • Humans have increased fixed nitrogen levels (smog, and acid rain HNO3 = Nitric acid)

38. Nitrogen Cycle • In this cycle, nitrogenous wastes and the remains of dead organisms are converted by decomposers and soil bacteria into compounds that can be used by autotrophs. • 5 steps • Nitrogen fixation N2NH3 • Nitrification NH3  NO2-  NO3- • Assimilation N-based compounds into tissues • Ammonification waste  NH3, NH+4, • Denitrification (NH3, NO2-, NO3-)  N2

39. The Nitrogen Cycle N2 Urea NH3, (NO2-, NO3-)

40. Nitrogen Cycle

41. Nitrogen Cycle

42. Nitrogen fixation Occurs in Legumes Roots (clover) N2NH3 Ammonification:  NH3, NH+4, Ammonifying bacteria use animal wastes (urea and uric acid) Nitrification: bacteria convert NH3  NO2-  NO3- Denitrification:Bacteria convert (Anaerobic nitrifying Bacteria) NH3  N2 NO2-  N2 NO3-  N2

43. Nitrogen Cycle • The Nitrogen cycle includes the following reactions: 1. Nitrogen Fixation: the conversion of N2 to NH3 (ammonia) by Nitrogen-fixing bacteria (Rhizobium in legume root nodules) as well as cyanobacteria (Anabaena & heterocysts). Nitrogen is “fixed” into a form that can be used. Bacteria use nitrogenase (shielded from O2) to split N2. Also lightning & volcanic activity.

44. Nitrogen Cycle • 2. Nitrification: the conversion of ammonia NH3 or ammonium NH4+ to NO3-.(when water reacts with ammonia). • Soil bacteria such as Nitrosomonas & Nitrococcus start NH3 or ammonium NH4+ to NO2- • Then Nitrobacter oxidizes NO2- to NO3-.

45. Nitrogen Cycle • 3. Assimilation: the conversion of inorganic N (NO3-, NH3, NH4+) to organic molecules (amino acids & proteins).

46. Nitrogen Cycle 4. Ammonification: the conversion of organic N (amino acids & proteins) to NH3 & NH4+, performed by Ammonifying bacteria. (Creating ammonia or ammonium) Conversion of Nitrogenous wastes:

47. Nitrogen Cycle

48. Nitrogen Cycle 5. Denitrification: the conversion (reduction) of NO3- to N2 performed by denitrifying bacteria.

49. The nitrogen cycle.

50. Nitrogen Cycle