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1. Photosynthesis Absorption and Conversion of Energy Click on Screen to Open

2. Autotrophs An autotroph is an organism that can make its own food through. auto: self troph:organism

3. All organisms must break down carbohydrates, or other complex molecules, to form energy molecules, such as Adenosine Triphosphate (ATP).]

4. Illustration by PROF. K.SEDDON & DR. T.EVANS, QUEEN'S UNIVERSITY BELFAST The chemical formula of ATP is C10H16 N5O16P3. ATP. Computer artwork of a molecule of adenosine triphosphate (ATP), which is a carrier of metabolic energy in the cell. Energy is stored in the chemical bonds and is released when the molecule is broken down.

5. 1.Light is the purest form of energy and the prime source of energy of all life. a. provides energy for photosynthesis b. visible spectrum: array of colors formed when white light passes througha prism c. photons: unit of light energy d. color of an object seen by the eye is the color of light reflected by the object Photograph by Stanley Mikles, September 2006, West of Emily Minnesota

6. 2. Chlorophyll Photo by Dr Tim Evans a. found in chloroplasts (in Eukaryotes) 1) plants 2) some algae b. found in cytoplasm of prokaryotes c. necessary for photosynthesis to begin d. absorbs energy from all but the green portion of the visible spectrum e. several types of chlorophylls are active

7. f. acts as a light (energy) trap during photosynthesis 1) when a photon strikes a chlorophyll molecule and is absorbed, the photon’s energy is transferred to an electron of the chlorophyll molecule 2) The energized electrons are stretched like rubber bands – but they cannot remain for long in this “excited state” a) raised to a higher energy level b) as electron returns to original level, it releases absorbed energy c) this energy is used in chemical reactions

8. 3. Other pigments are involved a. xanthophylls: yellow pigments that absorb light energy in other parts of the spectrum and pass the energy on to chlorophyll b. carotene: orange pigments

9. 4. Chloroplast: plastid that stores chlorophyll (plastid: sack) BIOPHOTO ASSOCIATES

10. a. photosynthesis begins in “thylakoid membrane” of a “granum” b. stroma: dense fluid that fills the space between the grana and the chloroplastic membrane PROF. KENNETH R. MILLER

11. DR KARI LOUNATMAA Pisum sativum

12. Starch Grain Pisum sativum DR JEREMY BURGESS

13. Coleus blumei Starch Grain DR JEREMY BURGESS

14. The Origin of Chloroplasts? Chloroplast Dividing

15. Photosynthesis occurs in two phases. I. Light-Dependent Reactions: Trapping of light energy and formation of materials needed in the next phase. A. light energy: photon: packet of light energy 1) c = 3.0 x 108 meters/second =186,000 mile/sec 2) E=mc2 3) Mass of photon: @ less than mass of electron (9.0 x 10-31kg)

16. B.chlorophyll molecules in thylakoid membranes (grana) of chloroplaststruck by photon

17. C. Chlorophyll molecular bonds broken releasing energy (excited electrons) 1. Excited electrons move down electron transport chain. a. Embedded In the thylakoid membrane are a series of proteins whose electrons are very excitable. b. The excited electrons move from protein to protein in the thylakoid. c. At each protein, the electrons lose energy. d. Some of the energy lost at each step is used to combine ADP and loose phosphate ions (P) to form ATP.

18. e. Some of the energy lost at each step is used to split water molecules through a process called hydrophotolysis. H2O H2 + O 1) H+ used in next phase First Photo System 2) O + O O2 O2 diffuses out of chloroplast into cytoplasm, diffuses out of cell and into intercellular space, diffuses to stomata, and is released by transpiration into the atmosphere. This is the source of 98% of all the free, molecular oxygen in our atmosphere. Open Stomata Photo by DR JEREMY BURGESS

19. Joseph Priestley (1733-1804 1. British chemist. 2. Best known as the discoverer of oxygen. 3. Carried out research into the composition and nature of air. 4. First person to recognize that respiration in animals produces carbon dioxide whereas in plants it produces oxygen. 5. In his work on carbon dioxide, Priestley invented soda water; the precursor to all carbonated drinks. 6. He was a Unitarian Calvinist minister and a supporter of the French Revolution. Eventually his political views led to his house being burnt down and him fleeing England. GEORGE BERNARD

20. SCIENCE PHOTO LIBRARYJoseph Priestley. This cartoon, of 1791 portrays Priestley, who supported the French revolution, as a political agitator. Priestley isolated and examined many new gases including hydrogen chloride, nitrous oxide, ammonia, nitrogen and carbon monoxide. He was also the first to isolate oxygen but did not correctly recognize its role in combustion, believing instead that it played a part in the 'phlogiston' (combustible element) theory. Priestley was persecuted for his religious and political beliefs. He left England in 1794.

21. f. “second photo system” and a “second electron transport chain” g. The “lost” energy at each protein jump is used to bond NADP to H. h. The energy is also used to transport the NADPH into the stroma by active transport. i. NADPH is used in the “light independent reactions”.

22. Light Independent Reactions • (aka: Dark Reactions, Dark Phase, Calvin Cycle) A. Energy stored in ATP (ADP + P ATP) used as energy source in Light Independent Reactions. B. CO2 from atmosphere supplies carbon and oxygen atoms for glucose. (C6H12O6) C. NADPH from light dependent reactions used a source of hydrogen used in glucose. D. Occurs in the stroma of the chloroplast

23. D. Light Independent Reactions (Calvin Cycle) 1. Carbon Fixation One molecule of CO2 is added to one molecule of RuBP (ribulose biphosphate), forming one unstable six carbon molecule. 2. Formation of two 3 – carbon molecules. The unstable 6 carbon molecule immediately breaks down into 2 3—carbon molecules of PGA. 3. Conversion of PGA to PGAL a. One molecule of ATP broken into ADP and P b. One NADPH broken into NAPD- and H+ c. Energy from ATP and NADPH forms the two PGA into 2 PGAL (phosphoglyceraldehyde).

24. Melvin Calvin LAWRENCE, BERKELEY NATIONAL LABORATORY 1941 Photographed in 1961.

25. 1.3. Reactions in the Calvin Cycle a. Co2 and a 5-carbon molecule (RuBP) combine to form a 6-carbon molecule: (unstable intermediate) “carbon fixation” b. H2O + 6 carbon molecule  2, 3-carbon molecules (2PGA) c. 1 ATP molecule broken--energy used to: d. NADPH + H+ NADP + H2 e. Result = 2, 3-carbon sugars (2PGAL) PGAL: Phosphoglyceraldehyde f. 1PGAL  6 carbon sugar (glucose: C6H12O6) g. 1PGAL returns to beginning of cycle h. ATP split: ATP  ADP + P + energy i. Yields return of 5-carbon molecule RuBP from 1PGAL (back to start)

26. III. Synthesis without sunlight: Chemosynthesis (bacteria) 1. methane producers 2. Chemoautotrophs 3. digestive tracts 4. break down of sewage 5. break down of oil spills

27. Stephen Hales (1677-1761) English chemist and physiologist. His book Vegetable Staticks (1727) describes 124 experiments on gases, which he made in several ways and collected using a pneumatic trough. He measured growth rates in plants, and showed that light is needed, and that water loss (by transpiration) is through the leaves and that this causes an upward flow of sap. Later experimented on blood pressure in animals and investigated the vascular system in general. Other studies involved the Preservation of foods, water purification, the ventilation of buildings and ships, and also the best way to support pie crusts.

28. Melvin Calvin LAWRENCE, BERKELEY NATIONAL LABORATORY 1941 Photographed in 1961.

29. Melvin Calvin. (born 1911), Portraits show Melvin Calvin, an American biochemist, in his photosynthesis research laboratory. He began to study photosynthesis in 1946 when sensitive analytical methods became available. He identified in single-celled Chlorella algae a cycle of photosynthetic reactions using radioactive forms of carbon dioxide. Photosynthesis is the process by which green plants convert light, water & carbon dioxide into food and oxygen. The discovery of this reductive pentose phosphate or Calvin cycle, which occurs in all photosynthesizing organisms, won Calvin the 1961 Nobel Chemistry Prize.