14. An excited electron is unstable and will drop back to the ground state and release its excess energy in the form of heat and fluorescence
15.
16. Linear Electron Flowthe flow of electrons through the photosystems A photon is absorbed by a pigment molecule in the light harvesting complex, exciting an electron As one electron falls back to ground state, another one rises This continues until the energy reaches the pair of chlorophyll a molecules in the reaction center complex in photosystem II An enzyme splits water in photosystem II into electrons, hydrogen ions, and oxygen The splitting of water molecules facilitates the flow of electrons through the electron transport chain to photosystem I to replace the electrons that were excited by light energy ATP is then synthesized from the energy created from the movement of electrons Light energy is transferred from the light harvesting complex pigments to the reaction center complex of photosystem I Photoexcited electrons move from the primary electron receptor of photosystem I to the second electron transport chain This is a light dependent reaction, creating NADPH and ATP which are then used in a light independent reaction, also known as the Calvin cycle
27. The amount of energy a photon has is related to how long the wavelength is
28.
29. Photoperiodism The reaction of plants in relation to the length of the day Plants use it to measure the seasons and to coordinate seasonal events such as flowering Plants can be described in relation to their photoperiod responses as short-day, long-day, and day neutral The length of daylight effects vegetative growth and reproductive activities in plants The length of darkness a plant experiences plays a more crucial role in whether a plant flowers or not
30.
31. Short day plants only form flowers when the length of the day is less than about 12 hours
33. Chrysanthemums, poinsettias, and goldenrods are examples of short day plantsThe chrysanthemum is in demand all year, which is why florist have to regulate their flowering using artificial lighting
34.
35. These flowers only bloom when they receive more than 12 hours of light each day
36. The best time of the year for long day plants to flower is late spring or early summer, when the days are longer (this is opposite in the southern hemisphere)
37. Many garden vegetables are long day plants such as potatoes, lettuce, and barleyAfter the summer solstice days become shorter, and long day plants are harvested shortly after.
38.
39. They flower regardless of day length, but flower earlier and more often with longer days
40. More often, the age of the plant, and temperature around it effect flowering
41. Beans, tomatoes, and roses fall into the category of day neutral plantsRoses are the most popular day neutral flowers
42. Works Cited Holley, Dennis. "Light and Temperature Influence Plant Growth." Suite101.com. N.p.,June, 11th, 2009. Web. 12 Oct 2010. <http://www.suite101.com/content/light-and-temperature-influence-plant-growth-a131226>. “Department of Physics." Florida Atlantic University. N.p.Web. 12 Oct 2010. <http://www.physics.fau.edu/observatory/lightpol-Plants.html>. "Plant Growth Factors: Light." Colorado Master Gardeners Program (2010): 142-1 to 142-4. Web. 11 Oct 2010. <http://www.cmg.colostate.edu/gardennotes/142.pdf>. howplantswork, . "Does the Moon Affect Plants? Part 2: Moonlight and Biorhythms." Wordpress. June, 25th, 2009. Web. 11 Oct 2010. <http://howplantswork.wordpress.com/2009/07/25/does-the-moon-affect-plants-part-2-moonlight-and-biorhythms/>.
43. Continued Leiser,Leopold,andShelley, . "Evaluation of light sources for plant growth.” Departments of horticulture and electrical engineering, Purdue university, Lafayette, Indiana 392-395. Web. 11 Oct 2010. <http://www.plantphysiol.org/cgi/reprint/35/3/392.pdf>. Lynn, Paul. Electricity from Sunlight. 1st ed. United Kingdom: John Wiley & Sons, 2010. Print. Tanaka, R., M. Rothbart, S. Oka, A. Takabayashi, K. Takahashi, M. Shibata, F. Myouga, R. Motohashi, K. Shinozaki, B. Grimm, and A. Tanaka. "LIL3, a light-harvesting-like protein, plays an essential role in chlorophyll and tocopherol biosynthesis. " Proceedings of the National Academy of Sciences of the United States of America 107.38 (2010): 16721. Research Library Core, ProQuest. Web. 5 Nov. 2010. Campbell, Reece, First. Biology, Photosynthesis. eighth ed. San Fransisco, California: Pearson Education, Inc., 2008. 185-203. Print.