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Photosynthesis: An Overview Chapter 8
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ATP Energy Storage
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How do heterotrophic organisms get energy? Consume “food.” Macromolecules that provide energy: Lipids Proteins Carbohydrates How do they use energy?
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ATP: Adenosine Triphosphate molecule energy-carrying molecule storage releasing Used for short term storage & releasing of energy Adenine Ribose 3 Phosphate Groups high energy bonds
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ADP and ATP are constantly being recycled recycled by the living cell Use energy to ADD phosphate group Break bond to LOSE phosphate group to release energy IN OUT
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NADP+ and NADPH are similar with adding a Hydrogen ATP ADPpartially ADP is like a partially-charged battery, ATPfully while ATP is said to be fully-charged. ADPATP Energy Adenosine triphosphate (ATP) Partially charged battery Fully charged battery
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Why do cells need energy? To carry out active transport Such as ion pumps To move organelles within the cell To synthesize (make) proteins & sugars for life functions ONE sugar molecule stores x90 more energy than ATP
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Photosynthesis Gathering Light Energy from the Sun
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PSN uses Visible Light from the SUN Travels in wavelengths Distance between crests determines color & energy Color seen is reflected, all others are absorbed
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Absorption of Light by Chlorophyll a and Chlorophyll b Section 8-2 Figure 8-5 Chlorophyll Light Absorption Pigments = molecules that reflect/absorb light Chlorophyll in chloroplasts photo-sensitive membrane captures solar energy Xanthophylls Carotenoids
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Chloroplasts In a plant Micrograph of a chloroplast
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Chloroplasts Structure
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Light Energy Chloroplast CO 2 + H 2 OSugars + O 2 Section 8-2 Photosynthesis: Reactants and Products PhotosynthesisPhotosynthesis time for a SCIENCE video
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Photosynthesis PART 1. Light-Dependent Reactions In the thylakoid Chlorophyll absorbs sun’s energy Energy transferred to electrons Like “Hot potatoes” H 2 0 SPLIT & O 2 is by products Charge up & Carry Energy NADP+ NADPH ADP ATP Think of these like an oven mitt to carry “hot potatoes”
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Photosynthesis Part 2. Light-Independent = Calvin Cycle (sunlight not directly needed) In the stroma CO 2 comes in and NADPH and ATP convert it to glucose (C 6 H 12 O 6 )
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The Photosynthesis Equation light 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Carbon Water Glucose Oxygen Dioxide (Sugar)
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8.3 The Reactions of Photosynthesis
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Light-dependent Reactions Photosystem: light capturing unit containing chlorophyll Electron transport system: electron carrier molecules that shuttle electrons, energy released to make ATP Electrons in chlorophyll must be replaced by electrons from water so that cycle may continue; oxygen is liberated from the light reactions Light reactions make ATP and NADPH used to fuel the reactions of the Calvin cycle (light independent reactions)
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Light Independent Reaction /Calvin Cycle ATP and NADPH from light reactions used to break CO 2 apart, then reassemble the carbons into glucose. Called carbon fixation: taking carbon from an inorganic molecule (atmospheric CO 2 ) and making an organic molecule out of it (glucose)
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In your comp book: Label the parts of a chloroplast on diagram provided p. 231 Organize information: Light-dependent reactions Light-independent reactions Definition Where take place Reactants Products
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