AP Bio: Wednesday, 11.24.10 Photosynthesis

1. AP Bio: Wednesday, 11.24.10Photosynthesis • Homework: • PS 10 due Tuesday after break • Do Now: • Take out the Photosynthesis Reading Worksheet • Get back and look over your quiz • Goals for Today: • Describe the details of the two stages of photosynthesis • How light energy is converted into chemical energy • How that energy is used to make glucose • Agenda: • Lecture: Photosynthesis • Work time w/ laptops on PS 10 • Cookies (products of photosynthesis)

2. Summary of Photosynthesis: Overall equation: 6CO2 + 6H2O + sunlight energy  C6H12O6 + 6O2 reduction oxidation

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6. Photosynthesis

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17. Photosynthesis Video

18. Phase 1: The Light Reactions

19. Phase 1: The Light Reactions stroma cytochromes (electron transport proteins) NADP+ reductase LIGHT LIGHT H+ e- NADP+ e- e- e- NADPH e- e- e- e- PS I e- PS II H2O thylakoid space ½ O2 + 2 H+ H+ to Calvin Cycle ATP synthase ADP ATP Pi H+

21. Summary of Light Reactions: • Water splits to donate electrons, and releases oxygen as waste • Electrons flow through ETC made of chlorophylls (photosystems) and cytochromes • ATP and NADPH are made (for use in the Calvin cycle)

22. Phase 2: Calvin Cycle

23. Phase 2: Calvin Cycle

27. Summary of Calvin Cycle: • Carbon (from CO2) is fixed by the enzyme Rubisco • Most fixed carbon is used to regenerate RuBP (the CO2 acceptor that starts the cycle) • Some fixed carbon is used to make a 3-carbon sugar that can form… • glucose (used for cell resp. or stored as starch) • sucrose (transported through rest of plant) [This is the whole point of photosynthesis!]

29. AP Bio: Monday, 11.29.10Photosynthesis: Challenges & Adaptations • Homework: • PS 10 due tomorrow • Do Now: • Read the Background Info and answer questions 1-2 on the handout • Goals for Today: • Describe photorespiration and explain why it’s bad for plants • Explain how C4 and CAM photosynthesis get around the challenge of photorespiration • Agenda: • Do Now • Quick explanation of photorespiration • Work in groups on C4 or CAM • If time: Present on C4 or CAM. If not, tomorrow.

30. Photorespiration – • The process in which the enzyme Rubisco fixes oxygen instead of carbon dioxide (in the first step of the Calvin cycle) • Due to Rubisco’s lack of specificity (it can use O2 or CO2 as a substrate) • Happens when stomates are closed (high O2 concentration and low CO2 concentration) • Wasteful – uses ATP and NADPH from light rxns, but makes no sugar!

31. Photosynthesis: Challenges & Adaptations • Goals for Today: • Describe photorespiration and explain why it’s bad for plants • Explain how C4 and CAM photosynthesis get around the challenge of photorespiration • In Groups of 3: • Use a textbook to figure out how C4 or CAM works to circumvent photorespiration • Answer the questions on your assigned page • Every member of your group should be ready to explain this to the class!

32. AP Bio: Tuesday, 11.30.10Photosynthesis: Challenges & Adaptations • Homework: • Lab 4 Pre-Lab (read procedure and answer pre-lab questions) • Do Now: (in your mind or your notebook) • What photosynthesis adaptation did your group study? • Both of these adaptations separate the initial step of carbon fixation from the actual Calvin cycle. Does your adaptation separate these things temporallyor spatially? • Goals for Today: • Explain how C4 and CAM photosynthesis get around the challenge of photorespiration • Agenda: • C4 and CAM presentations • Pre-Lab for Lab 4

33. AP Bio: Wednesday, 12.1.10Lab 4: Rates of Photosynthesis • Homework: • Lab 4 Graph and Analysis Questions • Do Now: • Take out Lab 4 • Goals for Today: • Predict and measure how _____ and __________ affect rates of photosynthesis • Explain how our experimental setup allows us to do this • Agenda: • Review Pre-Lab and experiment set-up • Set up chloroplast suspension • Do the lab!

34. Lab Groups for Today: • Surendra • Wilmene • Sohaila • Wilanda • Tracy • Leo • Elias • Hannah • Eliza • Sayed • Yanira • Alex Set up tubes now and come back 3rd or 4th period: • Gina • Shannon • Elaine • John • Cameron • Maria • Peter • Ned • Betsie • Juliana

35. AP Bio: Thursday, 12.2.10Cell Energetics Wrap-Up & Review • Homework: • Study for Test on Cell Respiration & Photosynthesis • Do Now: • Sit with your lab group from yesterday (but at the desks and front tables) • Take out Lab 4 • Volunteers draw graphs on the board • Goals for Today: • Explain the results of the photosynthesis lab • Compare and contrast cell respiration and photosynthesis • Review Cell Energetics by playing Jeopardy!

36. Compare/Contrast CR and P-sis In your notes, with your lab group: • Make a list or table in which you brainstorm all the similarities and differences between photosynthesis and cellular respiration • Include: • Broad Concepts • Specific Details

37. AP Bio:Monday, 12.6.10Test on Cellular Energetics • Homework: • Chapter 35 Reading Notes • Do Now: • Look over PS 10 • Get ready for the test • Goals for Today: • Demonstrate knowledge of cell respiration and photosynthesis by answering AP-style multiple choice and open response questions • Agenda: • Quick review of PS 10 • Test