Chapter 8 Photosynthesis

1. Chapter 8 Photosynthesis 8.1 Energy and Life 10/27/2005

2. What is Energy? • Ability to do work

3. Makes their own food Use the energy of the sun Ex. Plants Obtains energy from the foods they consume Autotrophs vs. Heterotrophs

4. ATP • Adenosine TriPhosphate • Made up of: • Adenine • 5 Carbon sugar (ribose) • Three phosphate groups • KEY TO STORE & RELEASE ENERGY

5. Storing Energy • ADP (Adenosine DiPhosphate) • Similar to ATP • 2 phosphate groups • Key to the way in which living things store energy • Add on available energy with a phosphate to ADP to create ATP • Analogy --> Battery

6. Releasing Energy • How is the energy stored in ATP released? • Breaking the chemical bond between the second and third phosphate group • Basic energy source of all cells

7. What is energy used for? • Carry out active transport • protein synthesis • Responses to chemical signals

8. ATP • can only pack small amounts of energy

9. P P Adenine Phosphate Ribose ADP

10. P P P Adenine Phosphate Ribose ATP

11. 8.2 Photosynthesis: An Overview

12. Photosynthesis • key cellular process identified with energy production • Who goes through photosynthesis? • PLANTS

13. Key Players • vanHelmont • Most of the gain in mass comes from water • Priestley • plant releases oxygen • Ingenhousz • Plant releases oxygen only with the presence of light

14. Photosynthesis Equation REACTANTS LIGHT 6CO2 6H2O + Carbon dioxide Water

15. Photosynthesis Equation PRODUCTS Sugar Oxygen LIGHT C6H12O6 + 6O2

16. Photosynthesis Equation LIGHT + 6CO2 6H2O C6H12O6 + 6O2 DESCRIBE WHAT IS HAPPENING IN THE REACTION. In photosynthesis, plants use the energy of sunlight to change water and carbon dioxide into high-energy sugars and oxygen.

17. Lights and Pigments • Plants need • Light • Form of energy • Pigment • light absorbing molecule • Chlorophyl • Principal pigment in plants

19. 8.3 The Reactions of Photosynthesis

20. Chloroplast • where photosynthesis takes place • thylakoid membranes = saclike photosynthetic materials found in chloroplast

21. Chloroplast • Granum = stack of thylakoid • photosystems = organization of chlorophyll and other pigments • light collecting units of the chloroplast

22. Photosystems • 2 part process • Light dependent • In the thylakoid membranes • Light independent (Calvin cycle) • In the stroma • Region outside the thylakoid membranes

24. Electron Carriers • Sunlight excites electrons in chlorophyll • electrons gain tons of energy • high energy electrons need special carriers from chlorophyll to other molecules

25. Electron Transport Chain • carrier molecule = compound that can accept a PAIR of high-energy electrons and transfer them to along with MOST of their energy

26. NADP+ • One of the carrier molecules • Nicotinamide adenine dinucleotide phosphate • Accepts and holds 2 high-energy electrons along with H+ (hydrogen ions) • This creates NADPH • NADP+ + H+ --> NADPH = converts energy sunglight into chemical form

27. NADPH • carries high-energy electrons produced by light absorption in chlorophyll to chemical reactions • used for synthesis of molecules

28. 2 high energy e- H+ NADP+ NADPH

29. 8.3B 11 / 13 / 06

30. Light Dependent Reactions • requires lights • uses energy from light to produce ATP and NADPH

31. Light Dependent Reactions • Products • OXYGEN GAS (02) • 2 energy carriers • ADP -- > ATP • NADP+ --> NADPH

32. Light Dependent Reaction 1. Photosystem II • Light breaks up H2O to have electrons, H+, and O • O2 is released into the air • H+ released into thylakoid membrane

33. Light Dependent Reaction 1. Photosystem II e- absorb light Creates high-energy electrons 2e- passed through e- transport chain

34. Light Dependent Reaction 2. Electron Transport Chain 2 high energy electrons provide Energy to move H+ from stroma INTO thylakoid membrane

35. Light Dependent Reaction 3. Photosystem I • Light re-energizes electrons • NADP+ picks up high energy electrons and H+ • H+ + NADP+ --> NADPH (electron carriers)

36. Light Dependent Reaction 4. Hydrogen Ion Movement • More H+ are pumped across the membrane • Inside = positive ions • Outside = more negative • Importance = provides energy to make ATP

37. Light Dependent Reaction 5. ATP Formation • ATP Synthase = protein on cell membrane • Allows H+ to pass through membrane • ATP Synthase binds ADP + P+, creating ATP

38. Light Dependent Reactions • Products • OXYGEN GAS (02) • 2 energy carriers • ADP -- > ATP • NADP+ --> NADPH

39. 8.3 C 11 / 14 / 06

40. Quickwrite 1. What

41. Calvin Cycle • uses ATP and NADPH from Light Dependent Reaction • Product - High energy Carbohydrates (sugar, starch)

42. A. CO2 Enters the Cycle Calvin Cycle • 6 CO2 enter the cycle from atmosphere • Combine with six 5-Carbon Molecules • Result = twelve 3-Carbon Molecules

43. B. Energy Input Calvin Cycle • ATP and electrons from NADPH used • 12 3-carbon molecules converted to higher energy forms

44. C. 6-Carbon Sugar Produced Calvin Cycle • Two 3-Carbon molecules are removed • produce sugars, lipids, amino acids, and other compounds for metabolism

45. D. 5-Carbon Molecules Regenerated Calvin Cycle • ATP is used • Ten 3-Carbon molecules convert back to six 5-Carbon molecules • 5-Carbon molecules combine with 6 CO2 molecules to begin the next cycle

46. Calvin Cycle • It takes 6CO2 to produce a SINGLE 6-Carbon sugar molecule • Removes CO2 from air • Sugar needed for growth and development

47. Create a Flow Chart 6 ____ go into cycle Combines with six ________ molecules Results = _____________ molecules

48. ATP and Electrons used from NADPH ____________ molecules converted into higher energy forms

49. Two __________ Molecules removed Produces _______________________________________________________

50. ______ 3-Carbon molecules converted back to 6 __________ molecule Cycle repeats!