Concept 2: Analyzing the Processes of Photosynthesis  Refer to pg in Holtzclaw, Ch 10 in Campbell and media resources  Refer to pg in Holtzclaw, Lab Inv 5 in Lab Manual

Try This!  Where does the biomass of a tree primarily come from? A.Oxygen B.Water C.Carbon dioxide D.Light E.Fertilizer

Try This!  Where does the biomass of a tree primarily come from? A.Oxygen B.Water C.Carbon dioxide D.Light E.Fertilizer

Try This! An acorn grows into an oak tree. The main source of the additional mass present in the oak tree is: a. Water from the soil b. Minerals from the soil c. CO 2 from the air

Try This! An acorn grows into an oak tree. The main source of the additional mass present in the oak tree is: a. Water from the soil b. Minerals from the soil c. CO 2 from the air

Photosynthesis (Chapter 10) You must know:  The summary equation of photosynthesis including the source and fate of reactants and products  How the leaf and chloroplast anatomy relates to photosynthesis  How photosystems convert solar energy to chemical energy  How linear electron flow in the light reactions results in the formation of ATP, NADPH, and O 2  How chemiosmosis generates ATP in the light reactions  How the Calvin cycle uses the energy molecules of the light reactions to produce G3P

Photosynthesis – The Basics CO 2 + H 2 O → C 6 H 12 O 6 + O 2 1)Light Reactions “photo” 2)Calvin Cycle “synthesis”

The Light Reactions  Light energy excites electrons in chlorophyll  Removal of electrons from H 2 O  Formation of O 2  Electron Transport Chain  Reduction of NADP + to NADPH  Proton Motive Force  ATP Synthase to produce ATP

Try This  Unlike in cellular respiration, the proton motive force generated by the light reactions in photosynthesis happens in three ways… Can you remember the three ways? 1. Electron transport chain powering the active transport of H + into the thylakoid space 2.H + produced in the thylakoid space from the splitting and oxidation of water 3. Removal of H + from stroma during the reduction of NADP + to NADPH

The Light Reactions  Light energy excites electrons in chlorophyll  Removal of electrons from H 2 O  Formation of O 2 (leaves stomata as a gas)  Electron Transport Chain  Reduction of NADP + to NADPH  Proton Motive Force  ATP Synthase to produce ATP

The Light Reactions  The whole point was to transfer light energy to chemical energy in the form of:  electrons in NADPH  ATP  Why?  To power carbon fixation in the Calvin Cycle…

The Calvin Cycle  CO 2 enters as a gas through the stomata (openings) of the leaves  Through the power of NADPH and ATP, CO 2 gets converted into an organic compound: a 3-carbon sugar called glyceraldehyde-3-phosphate (G3P)  Can be converted to glucose, sucrose, starch, etc…

Try This!  Which experiment will produce 18 O 2 ? A.Exp 1 B.Exp 2 C.Both! D.Neither!

Try This!  Which experiment will produce 18 O 2 ? A.Exp 1 B.Exp 2 C.Both! D.Neither!

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Next Class…  Adaptations to hot, arid climates …  CAM plants and C 4 plants

Now…  Practice  Try #12 – 15, 17-19, p  Go over Comparison Charts  Try animation activities (Campbell Online)  Read about CAM plants and C 4 plants  P Holtzclaw  P Campbell  Activity: Photosynthesis in Dry Climates (Campbell Online)