1. 8.1 How Organisms Obtain Energy Mr. Purcell Biology I

2. Transformation of Energy Energy is the ability to do work. Thermodynamics is the study of the flow and transformation of energy in the universe.

3. Laws of Thermodynamics First law – Energy can not be created nor destroyed only changed. Second law – Energy cannot be converted without the loss of usable energy.

4. Autotrophs and Heterotrophs Autotrophs are organisms that make their own food. Heterotrophs are organisms that need to ingest food to obtain energy.

5. Metabolism All of the chemical reactions in a cell. Photosynthesis –light energy from the sun is converted to chemical energy for use by the cell. Cellular respiration – organic molecules are broken down to release energy for use by the cell

6. ATP: The Unit of Cellular Energy Adenosine Triphosphate (ATP) – Cells use ATP to store & use for Energy (Battery fully charged) Adenosine Diphosphate (ADP) – Stores Energy (Battery Not fully Charged)

7. ATP & ADP -To release the Energy, the Phosphate Bonds are Broken -Cells only have very small amounts of ATP on hand, most is in ADP & is easily converted to ATP.

8. ATP Synthesis

9. 8.2 Photosynthesis

10. Photosynthesis… …way simplified

11. Photosynthesis

13. Overview of Photosynthesis Photosynthesis occurs in two phases. Light-dependent reactions Light–independent reactions (Calvin Cycle) light 6CO 2 + 6H 2 O C 6 H 12 O 6 +6O 2

14. Light Dependent Reactants Need the light dependent reactants 3:25 clip Have on Hadorn chapter 8 Light dependent reactants

15. Photosynthesis – Absorption Spectra

16. Chlorophyll

17. Chlorophyll…

18. Phase One: Light Reactions The absorption of light is the first step in photosynthesis Chloroplasts capture light energy.

19. Chloroplast

21. Calvin Cycle

22. Electron transport Light energy excites electrons in photosystem II and also causes a water molecule to split, releasing an electron into the electron transport system, H + into the thylakoid space, and O 2 as a waste product.

23. No I will not…

24. Electron Transport The excited electrons move from photosystem II to an electron –acceptor molecule in the thylakoid membrane. That transfers the electrons along a series of electron – carriers to photosystem I.

25. Electron Transport Photosystem I transfers the electrons to a protein called ferrodoxin. Ferrodoxin transfers the electrons to the electron carrier NADP + forming the energy – storing molecule NADPH.

26. Need electron chain clip

27. ADP+  ATP The H+ from the split of water is used by ATP Synthase to produce ATP from ADP+.

28. Electron Transport

30. http://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/d l/free/0072437316/120072/bio13.swf::Photosynthetic%20Ele ctron%20Transport%20and%20ATP%20Synthesis

31. Phase Two: The Calvin Cycle In the second phase of photosynthesis, called the Calvin cycle, which takes place in the stroma, ATP and NADPH from the light-dependent reactions are used to produce high-energy sugars.

32. The ‘Melvin’ Calvin cycle works steadily to remove carbon dioxide from the atmosphere and turns out energy-rich sugars. Six carbon dioxide molecules are needed to make a single 6-carbon sugar. Phase Two: The Calvin Cycle

33. The Calvin Cycle

35. Photosynthesis

36. Alternative pathways C 4 plants CAM plants

37. C4 and CAM 4 Plants

38. Photosynthesis The Musical

39. 8.2 – Section Review

40. 8.3 Cellular Respiration Overview of Cellular Respiration Organisms obtain energy in a process called cellular respiration. The equation for cellular respiration is the opposite of the equation for photosynthesis. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy

41. Cellular respiration occurs in three main parts. 1. Glycolysis 2. The Kreb Cycle 3. Electron Transport

43. Glycolysis Glucose is broken down in the cytoplasm through the process of glycolysis. Two molecules of ATP and two molecules of NADH are formed for each molecule of glucose that is broken down.

44. Glycolysis

45. Krebs Cycle Glycolysis has a net result of only two ATP and 2 pyruvate. Most of the energy from the glucose is still contained in the pyruvate. This series of reactions in which pyruvate is broken down into carbon dioxide is called the Krebs cycle.

46. Krebs Cycle The net yield from the Krebs cycle is six CO 2 molecules, two ATP, eight NADH, and two F ADH2.

47. Electron Transport Final step in the breakdown of glucose Point at which most ATP is produced Produces 34 ATP

50. What happens when we run out of OXYGEN?

51. Anaerobic Respiration The anaerobic pathway that follows glycolysis. Two main types Lactic acid fermentation Alcohol fermentation

52. Fermentation

54. Chemiosmosis

55. Electron Transport

56. Photosynthesis and Cellular Respiration