Energy Transformation: Photosynthesis (Outline) 1. Overview of photosynthesis 2. Producers, consumers, and decomposers of the ecosystem (source of carbon and energy): Autotrophs & Heterotrophs 3. Plant structures: organ, tissue, cells, sub-cellular organelle, and molecules. 4. Visible Light and its wavelengths 5. Chloroplast structure 5. Overview of the two processes or pathways of photosynthesis Light reactions: Substrates, products, cellular components and their location Calvin cycle: Substrates, products, cellular components and their location 6. Current Connections
Living organisms interact with their environment transforming energy Sun Air Inflow of light energy CO 2 O 2 CO 2 Chemical energy Loss of heat energy Producers Cycling of Chemical nutrients Consumers H 2 O Ecosystem Decomposers Soil Energy flow and recycling of material
Overall equation for photosynthesis Overall equation for cellular respiration
Producers of the ecosystem Autotrophs Produce their own food and sustain themselves without eating other organisms Bacteria Algae Plants
In plant cells, energy of light is converted to ATP and reducing power (NADPH), which are then used for converting CO 2 into sugar
In plants, photosynthesis takes place in green leaves Leaf Cross Section Mesophyll Cell TEM 9,750 Leaf Vein Grana Stroma CO 2 O 2 Chloroplast Stroma Granum Mesophyll Stoma Chloroplast ThylakoidThylakoid space LM 2,600 Outer membrane Inner membrane Intermembrane space
Overview of Photosynthesis 1. Light 2. Chloroplast Thylakoids (stacked as grana) The Light Reactions Stroma The Calvin Cycle Chloroplast Outer membrane Stroma Inner membrane Grana Stroma Granum Thylakoid Thylakoid space Intermembrane space
The Light Reactions - Converts light energy to chemical energy (ATP & NADPH) - Produces O 2 from breakdown of water The Calvin cycle - uses ATP & NADPH from light reactions to assemble sugar molecules from CO 2 H 2 O Chloroplast CO 2 Light NADP + LIGHT REACTIONS (in thylakoids) + P ATP NADPH CALVIN CYCLE (in stroma) Figure 7.5 O 2 Sugar
Chloroplasts Thylakoids (stacked as grana) Thylakoid membrane Photosystems: PS Chlorophyll Stroma
H 2 O Chloroplast CO 2 Light LIGHT REACTIONS (in thylakoids) NADP + ADP + P CALVIN CYCLE (in stroma) ATP NADPH Figure 7.5 O Sugar
Summary of the Light Reaction
THE CALVIN CYCLE: CONVERTING CO 2 TO SUGARS Calvin cycle Occurs in the chloroplast s stroma ATP and NADPH power sugar synthesis The first sugar molecule is G3P (3C) that is used to build glucose and other organic molecules Input CO 2 ATP NADPH RuBP CALVIN CYCLE Output: G3P
Summary of Calvin Cycle
Review: Photosynthesis uses light energy to make food molecules Light H 2 O CO 2 Chloroplast Photosystem II Electron transport chains Thylakoid Photosystem I membranes O 2 LIGHT REACTIONS NADP + ADP P + ATP NADPH RUBP CALVIN CYCLE 3-PGA (in stroma) G3P Sugars CALVIN CYCLE Stroma Cellular respiration Cellulose Starch Other organic compounds
Current Connections Cellular Fuel, Fossil Fuel, and Biofuel Heat and pressure & no air gas and unrefined oil move through small holes in rocks collect in reservoirs http://chemwiki.ucdavis.edu/@api/deki/files/3695/=the_creation_of_fossil_fuels.pdf
Fossil Fuel: Oil and Gas formation https://www.youtube.com/watch?v=8yhsxxevb1m (3:05 minutes)
Photosynthesis, Solar Radiation, and Earth s Atmosphere Two current global issues would affect life as we know it on earth: - Sources of energy (Fossil fuel & Bio fuel) - Global warming- CO 2 emission (Greenhouse effect) Greenhouses used to grow plant trap solar radiation, raising the temperature inside
Greenhouses used to grow plant trap solar radiation, raising the temperature inside
Excess CO 2 in the atmosphere traps solar energy raising the temperature on earth contributing to global warming Sunlight Some heat energy escapes into space ATMOSPHERE Radiant heat trapped by CO 2 and other gases Environmental Tech DVD-Chapter 2
NEWS Flash: Sept. 27, 2016 We just passed a CO2 threshold of 400 ppm https://www.co2.earth/daily-co2 http://www.scientificamerican.com/article/earth-s-co2-passes-the-400-ppm-thresholdmaybe-permanently/