Chapter Six Photosynthesis 6.1 Light Cycle 6.2 Dark Cycle

1. The Biology of CreationStudying God’s World (Science) in the Light of God’s Word (Scripture)Mr. Galloway • Chapter Six • Photosynthesis • 6.1 Light Cycle6.2 Dark Cycle www.soulcare.org Sid Galloway

2. Animations • http://www.abdn.ac.uk/~clt011/flash/samples/photosyn.swf • Interactive Animation of Photosynthesis • http://www.web.virginia.edu/gg_demo/movies/figure18_12b.html • Excellent interactive • http://www.fw.vt.edu/dendro/forestbiology/photosynthesis.swf • http://www.cst.cmich.edu/users/baile1re/bio101fall/enzphoto/photoanima.htm • http://science.nhmccd.edu/biol/bio1int.htm www.soulcare.org Sid Galloway

3. (Lab) Chloroplasts in Elodea www.soulcare.org Sid Galloway

4. LAB Review Animation • Elodea Plasmolysis Experiment • http://ccollege.hccs.cc.tx.us/instru/Biology/AllStudyPages/Diffusion_Osmosis/Elodeagif.swf • http://www.hccs.edu/nmc/ www.soulcare.org Sid Galloway

5. Spiritual Analogy & Application: • Elodea’s common name is “Anacharis” meaning “increased GRACE / GIFT (charis)” in Greek.  Just as our Creator God gave plants to continually provide life-giving air (oxygen) to His nephesh (thinking / feeling) creatures, God has also given us the Holy Spirit as the source of new, eternal life through the second birth spiritually when a person is “born-again”.  By the way, the New Testament Greek word for spirit is pneuma, which means air or wind.  Therefore, without the new, spiritual, second birth, no person can have eternal life.  Jesus said the choice is yours (John 3).  The Good News (Gospel) is that Jesus did all the work necessary for us, through His sinless life, sacrificial death, and resurrection.  None of our tainted “good” works are of any value to earn or buy eternal life. www.soulcare.org Sid Galloway

6. Photosynthesis = process by which a cell captures the energy in sunlight and uses it to make food. Plants, algae, and some bacteria use this process. Like a Solar Powered Calculator with light capturing cells www.soulcare.org Sid Galloway

7. Man’s Simple Solar Cell www.soulcare.org Sid Galloway

8. Solar Cell www.soulcare.org Sid Galloway

9. God’s Super Solar Panel www.soulcare.org Sid Galloway

10. Tech. Research News 2004 • “Plants and photosynthetic bacteria contain molecules that convert photons to energy very efficiently. The trick to harnessing these molecules for solar cells is marrying these relatively delicate molecules with electronics. “Researchers from the Massachusetts Institute of Technology, the U.S. Naval Research Laboratory, and the University of Tennessee have mixed biology and electronics in solar cells that use photosynthetic spinach leaf molecules or photosynthetic bacteria to convert light to electricity. “When light shines on the spinach leaf molecules and photosynthetic bacteria they produce an electrical current that is captured by electrical contacts.” • http://www.trnmag.com/Stories/2004/082504/Photosynthesis_drives_solar_cell_Brief_082504.html www.soulcare.org Sid Galloway

11. Water Sun Light Carbon Dioxide Photosynthesis Sugar Oxygen Cellular Respiration Energy - ATP www.soulcare.org Sid Galloway

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13. God’s Super Solar Cell www.soulcare.org Sid Galloway

14. ATP Molecule www.soulcare.org Sid Galloway

15. Consumption of ADP (1 blue plus 2 red phosphates) and a phosphate (1 red) to produce ATP (1 bue and 3 reds). This synthesis is driven by the proton-motive force which is depicted as white spheres leaving through the ATP-synthase. www.soulcare.org Sid Galloway

16. ATP Synthase Motor www.soulcare.org Sid Galloway

17. ATP Factor Motor www.soulcare.org Sid Galloway

18. http://www.sigmaaldrich.com/B2B/Area_of_Interest/Biochemicals/Enzyme_Explorer/Key_Resources/Metabolic_Pathways/ATP_Synthase.htmlhttp://www.sigmaaldrich.com/B2B/Area_of_Interest/Biochemicals/Enzyme_Explorer/Key_Resources/Metabolic_Pathways/ATP_Synthase.html www.soulcare.org Sid Galloway

19. Autotrophsmake their own food, and most use photosynthesis to do it. * Plants are the most common, but algae and some bacteria use it. * All life depends on autotrophs (directly or indirectly) for food. * Nearly all living things obtain energy either directly (like plants) or indirectly (like heterotrophs that eat plants) from the sun’s energy captured during photosynthesis. www.soulcare.org Sid Galloway

20. Photosynthesis (Simply Summarized) Leaves of plants have chloroplasts that are filled with chlorophyll, which capture the energy from the sunlight). * Water enters through the roots. * CO2 enters through stomata openings on the underside of the leaves.* Water and CO2 move to the chloroplasts. * Chemical reactions there, produce (O2) and sugars like glucose (C6H12O6).* Cells then use the energy in the sugars (carbohydrates) to function. www.soulcare.org Sid Galloway

21. Photosynthesis Equation: CO2 +H2O + light energy → Sugar (glucose) +O2 More Detailed (Balanced) Equation: Using Light Energy carbon dioxide water “yields glucose oxygen 6CO2 +6H2O → C6H12O6 +6O2 www.soulcare.org Sid Galloway

22. Biochemical Pathway =Series of linked chemical reactions, in which the product of one reaction is consumed (used as the reactant) in the next reaction. * The two stages of photosynthesis involve biochemical pathways. * Also, the final products of plant photosynthesis (sugar and oxygen) are used by animals for another process called cellular respiration. The products of respiration are carbon dioxide and water, which plants need for photosynthesis, so both processes create a balance in the atmosphere. www.soulcare.org Sid Galloway

23. The Photosynthesis Reactions: 1. Light Reactions are the first set of reactions in photosynthesis. Background information about light: Sunlight appears white, but really many colors. Visible Spectrum = the light waves we can see. Wavelength = distance between wave crests (Different wavelengths reflected as different colors.) (Objects absorb and reflect certain waves.) www.soulcare.org Sid Galloway

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25. * Light is absorbed in the membranes of thylakoids founds in chloroplasts. - Grana = stacks of flat thylakoids.- Stroma = the solution surrounding the thylakoids.- Chlorophylls = pigments, which absorb violet, blue, red, yet reflect green. - Pigment = a compound that absorbs light waves. (Chlorophyll “a” is directly involved in light reactions. - Accessory Pigments = indirectly assist other pigments. ( Chlorophyll “b” is an accessory pigment assisting “a”.) Carotenoids are other accessory pigments (yellow, orange, brown, etc.) (They absorb blue and green light.) (In the fall, plant leaves turn color because they lose chlorophylls, which reflect green light.) www.soulcare.org Sid Galloway

26. The Light Reaction in the Thylakoid Membrane www.soulcare.org Sid Galloway

27. Electron Transport System of the light reactions. * Photosystem = cluster of pigment molecules grouped in the thylakoid membrane. Twotypes: Photosystem II – Actually begins the process Photosystem I – Called “1” is believed to have evolved first. * Accessory pigment molecules start the light reactions by absorbing light energy. (It is passed to other pigment molecules until it reaches chlorophyll a molecules.)* Then a FIVESTEP process occurs . . . . . . . . www.soulcare.org Sid Galloway

28. FIVESTEPS of the Electron Transport System • Light excites electrons in the chlorophyll a molecules of photosystem II. (Oxidation reaction, since it loses an electron.) • These electrons move to and are accepted by a primary electron acceptor. (This is a reduction reaction.) • The electrons are then transferred along a series of molecules called an electron transport chain. • Light excites electrons in chlorophyll a molecules of photosystem I. • Electrons from Photosystem I are transferred along a second chain. (The chain ends as they combine with organic NADP+and H+ making NADPH.) www.soulcare.org Sid Galloway

29. Restoring Photosystem II Electrons by splitting Water Molecules: * Enzyme splits water to protons, electrons, & oxygen 2H2O → 4H+ +4e- + O2 So oxygen is a by-product of light reactions, and not used in the rest of photosynthesis. (The oxygen is used by other organisms for cellular respiration.) www.soulcare.org Sid Galloway

30. Chemiosmosis = a process in light reactions that synthesizes (makes) ATP. * Protons produced from the water splitting build up inside the thylakoid, and they then move down their gradient to the outside. * ATP Synthase is a multifunctional protein serving as an enzyme and carrier protein.It uses the energy of the moving protons to add a phosphate group to ADP and make ATP (A primary chemical energy storage molecule for energy currency in the cell.)* ATP and the NADPH provide energy for the second set of photosynthesis reactions, called the Calvin Cycle. www.soulcare.org Sid Galloway

31. The Light Reaction in the Thylakoid Membrane Primary electron acceptor Primary electron acceptor Photosystem II Electron Transport Chain Photosystem I Electron Transport Chain Animation here:http://www.stolaf.edu/people/giannini/flashanimat/metabolism/photosynthesis.swf www.soulcare.org Sid Galloway

32. 2. The Calvin Cycle= second set of reactions (pathway), producing organic compounds from the stored energy of ATP and NADPH.* Occurs in the stroma of the chloroplast. * Carbon Fixation: C atoms from CO2 are bonded (“fixed”) into organic compounds.(amino acids, lipids, and carbohydrates like glucose, fructose) (Note: These compounds are not directly produced by photosynthesis.) www.soulcare.org Sid Galloway

33. Three Steps of the Calvin Cycle: a. CO2 combines with RuBP to form two molecules of PGA.b. Each molecule of PGA is converted into a molecule of PGAL.c. Most of the PGAL is converted back into RuBP, but some PGAL can be used later to make different organic compounds.* RuBP = five-carbon carbohydrate. * PGA and PGAL are both three-carbon molecule* C3 Plants (produce the 3-Carbon PGA), and use only the Calvin Cycle for carbon fixation. www.soulcare.org Sid Galloway

34. The Two Processes Visualized www.soulcare.org Sid Galloway

35. Alternative Pathways * First, remember that C3 Plants are those that only use the Calvin Cycle to fix carbon. - They are called C3 plants, since they fix CO2 into a compound with 3 carbons (PGAL). * Others in hot, dry climates supplement the Calvin cycle with alternatives (C4 or CAM), because their stomata openings in the leaves must close to preserve moisture, so the amount of CO2 they absorb is reduced. www.soulcare.org Sid Galloway

36. C4 Pathway – use an enzyme which fixes CO2 into compounds with 4 carbons, which are then transported to other cells where CO2 is available to then use the Calvin Cycle.(corn, sugar cane, are examples) CAM Pathway – These plants open the stomata only at night to reduce water loss.They take in and fix it into compounds, which then release it during the day for use in the Calvin Cycle.(cactuses, pineapples, etc.) www.soulcare.org Sid Galloway

37. Rate of Photosynthesis * Increases as either light intensity or CO2 increase, but eventually plateaus at a maximum. * Increases as the temperature increases, up to a certain temperature.(Beyond a certain high temperature, the rate of photosynthesis decreases.) www.soulcare.org Sid Galloway

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40. Rate due to Light www.soulcare.org Sid Galloway

41. Rate due to Light www.soulcare.org Sid Galloway

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43. Calvin Cycle www.soulcare.org Sid Galloway

44. Calvin Cycle www.soulcare.org Sid Galloway

45. Calvin Cycle www.soulcare.org Sid Galloway

46. Cellular Respiration www.soulcare.org Sid Galloway