Photosynthesis

1. Photosynthesis Biology 1114

2. Autotrophs “Self Feeders” Photosynthesize Plants Algae / Protists Some Bacteria

3. A Large Proportion of Photosynthesis (40%-50%) Takes Place in the Oceans of the World and is Carried Out by Plankton

4. Photosynthesis “The conversion of light energy from the sun into chemical energy” • Light Energy is converted into Chemical Energy • Organisms trap the Sun’s Energy to Build Carbohydrates

5. chlorophyll 6CO2 + 12 H2O + Light Energy------------------------> C6H12O6 + 6O2 + 6 H2O enzymes

6. Photosynthesis Enables Societies to Function and is the Sole Means of Sustaining Life

7. Utilization of Photosynthetic Sugars • Wood • Fibers • Stored Carbohydrates • Amino Acids • Clothing • Shelter • Food

8. Photosynthesis Provides Consumers with Energy Through the Ingestion of Producers

9. Ozone Protects us from UV Radiation from the Sun

10. As you know, the increase in UV radiation due to ozone loss is very damaging to complex molecules, which are an essential ingredient for life as we know it.

11. Skin Cancer

15. Scientists say ozone layer recovery may not be detectable for as many as 45 years.

16. Fossil Fuels

17. Photosynthesis chlorophyll 6CO2 + 12 H2O + Light Energy------------------------> C6H12O6 + 6O2 + 6 H2O enzymes

18. Photosynthesis • Energy of the sun is transformed into chemical energy stored in food • Not 100% efficient • Not all sunlight falls on producers • Some absorbed energy is subsequently released and lost

19. Photosynthesis chlorophyll 6CO2 + 12 H2O + Light Energy------------------------> C6H12O6 + 6O2 + 6 H2O enzymes Photosynthesis changes two low energy molecules (Carbon Dioxide and Water) into a high energy molecule (Sugar).

20. Jon Baptista von Helmont, a 17th century Flemish physician started getting a handle on what happens when plants grow in the soil with his "tree experiment." He was trying to measure how soil matter was displaced when plants grow. To do this, he planted a willow tree in a large earthen tub. He planted a 5-pound sprig into 200 pounds of soil. The tub was then covered except for a small hole for the tree trunk and one for watering. Five years later, the tree weighed 164 pounds. Von Helmont reasoned if the tree had picked up the difference between 5 pounds and 164 pounds, then the soil in the tub should weigh only 41 pounds. The results proved him wrong! After oven drying the soil, he'found the 200 pounds of soil had only lost 2 ounces. Von Helmont Experiment

21. Where Does Photosynthesis Occur?

24. Light Dependent Reactions Require Sunlight to Convert Light Energy into Chemical Energy This Chemical Energy is Stored in ATP and NADPH The Thylakoid Membranes contain all the pigments and all the enzymes necessary for the light phase of photosynthesis.

25. Light Independent Reactions Do Not Require Sunlight They Assemble Sugars by Using ATP and NADPH The fluid in the stroma contains most of the enzymes necessary for the dark phase of photosynthesis

26. Necessary Molecules of Matter • Carbon Dioxide • .035% • Diffuses through Stomata • Removed by Photosynthesis • Returned by Respiration

28. Necessary Molecules of Matter • Water • Taken up through Roots • <1% used by Photosynthesis • >99% lost via Transpiration

29. Light • Exhibits Properties of Both waves and Particles of Energy • Electromagnetic Spectrum • Visible Light is Involved in Photosynthesis

30. High Energy Low Energy

31. Electromagnetic Spectrum High Energy Gamma RaysShort Wavelength X-Rays Ultra Violet Visible Light Infrared Microwaves Low Energy Radio Waves Long Wavelength

32. Visible Light (Roy G. Biv) High Energy VioletShort Wavelength Indigo Blue Green Yellow Orange Low Energy Red Long Wavelength

33. Light Energy is Absorbed by Pigment Molecules Each Pigment Has a Characteristic Absorption Spectrum

35. The Reactions of Photosynthesis • Photosynthesis begins with the light-dependent reactions. • Light-dependent reactions are followed by light-independent reactions

36. Essentials and General Overview

37. Summation of Light Dependent Rxn

38. Do What? • During the light-dependent reactions 1. Light Energy is Absorbed 2. Water is Split 3. ATP and NADPH is Formed Note: At this point Carbon Dioxide has not been used and no sugars have been produced.

39. Light Energy from the Sun is Transferred to Chlorophyll in Plants Chlorophyll Passes Energy Down Through the Electron Transport Chain Providing Energy to do Two Things Split Water P + ADP  ATP O2 is Released 2H+ and NADPH For Use in the Light-Independent Reaction

40. Light Independent Reactions or Calvin Cycle • Stroma • Light or Dark • Requires 1. Carbon Dioxide 2. Hydrogen Protons and Electrons 3. ATP 4. Enzymes 5. RUBP

42. Do What? • During the light-independent reactions 1. Carbon Dioxide and Hydrogen Combine to Make Sugar 2. Sugar Contains High Energy Bonds 3. Process Occurs by Phosphorylation Note: The two reactions (Light and Dark) are complementary to one another.

43. Essentials of Photosynthesis • Two Reactions Complete the Process • Carbon Dioxide Combines with Hydrogen Atoms from Water to Make Sugar Molecules • Some of the energy that was initially absorbed by the plant in the form of sunlight, and which was temporarily stored in the bonds of ATP (and NADPH) ends up stored in the bonds of the sugar molecules. Since it utilizes the chemical energy in ATP and NADPH, it does not require sunlight

44. Essentials of Photosynthesis • This is a complex cycle of mostly adding or removing phosphate (phosphorylation) and moving electrons in chemical reactions. • The two reactions (Light and Dark) are complementary of one another.