Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Photosynthesis Biology 1114 Autotrophs “Self Feeders” Photosynthesize Plants Algae / Protists Some Bacteria A Large Proportion of Photosynthesis (40%-50%) Takes Place in the Oceans of the World and is Carried Out by Plankton 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 chlorophyll 6CO2 + 12 H2O + Light Energy------------------------> C6H12O6 + 6O2 + 6 H2O enzymes Photosynthesis Enables Societies to Function and is the Sole Means of Sustaining Life Utilization of Photosynthetic Sugars • • • • • • • Wood Fibers Stored Carbohydrates Amino Acids Clothing Shelter Food Photosynthesis Provides Consumers with Energy Through the Ingestion of Producers Ozone Protects us from UV Radiation from the Sun 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. Skin Cancer Scientists say ozone layer recovery may not be detectable for as many as 45 years. Fossil Fuels Photosynthesis chlorophyll 6CO2 + 12 H2O + Light Energy------------------------> C6H12O6 + 6O2 + 6 H2O enzymes 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 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). Von Helmont Experiment 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. Where Does Photosynthesis Occur? 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. 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 Necessary Molecules of Matter • Carbon Dioxide – .035% – Diffuses through Stomata – Removed by Photosynthesis – Returned by Respiration Necessary Molecules of Matter • Water – Taken up through Roots – <1% used by Photosynthesis – >99% lost via Transpiration Light • Exhibits Properties of Both waves and Particles of Energy • Electromagnetic Spectrum • Visible Light is Involved in Photosynthesis High Energy Low Energy Electromagnetic Spectrum High Energy Low Energy Gamma Rays X-Rays Ultra Violet Visible Light Infrared Microwaves Radio Waves Short Wavelength Long Wavelength Visible Light (Roy G. Biv) High Energy Low Energy Violet Indigo Blue Green Yellow Orange Red Short Wavelength Long Wavelength Light Energy is Absorbed by Pigment Molecules Each Pigment Has a Characteristic Absorption Spectrum The Reactions of Photosynthesis 1. Photosynthesis begins with the lightdependent reactions. 2. Light-dependent reactions are followed by light-independent reactions Essentials and General Overview Summation of Light Dependent Rxn 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. 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 O2 is Released 2H+ and NADPH P + ADP ATP For Use in the LightIndependent Reaction Light Independent Reactions or Calvin Cycle • Stroma • Light or Dark • Requires 1. 2. 3. 4. 5. Carbon Dioxide Hydrogen Protons and Electrons ATP Enzymes RUBP 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. 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 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.