Comparing Photosynthesis & Respiration
Mitochondrion and Chloroplast structure
Process of storing energy in sugar molecules from the energy initially in the sun (radiant energy)1st step: Capture radiant energy and use it to generate our energy currency2nd step: Use energy currency to convert CO2 to glucoseOxygen is released as a byproductHappens in the chloroplast
WHY ARE PLANTS GREEN?It has to do with sunlight!
Sunlight is a form of electromagnetic energy, which travels in waves.
Different wavelengths of visible light are seen by the human eye as different colors.WHY ARE PLANTS GREEN?Gamma raysX-raysUVInfraredMicro- wavesRadiowavesVisible light
Sunlight minus absorbed wavelengths or colors equals the apparent color of an object.The feathers of male cardinals are loaded with carotenoid pigments. These pigments absorb some wavelengths of light and reflect others. Reflected light
Chloroplast PigmentsChloroplasts contain several pigmentsPigments are materials that absorb particular wavelengths of light and reflect others Chlorophyll a: absorbs mainly violet and red light the bestChlorophyll b: absorbs blue and orange light the bestCarotenoids: absorbs blue and green best* When chlorophyll absorbs light, energy is transferred to electrons and boosts them to a higher state.Figure 7.7
Different pigments absorb light differently
Photosystems:Clusters of pigments in thylakoid membrane
Traps light energy and transfers the light-excited electrons to an electron transport chain.
Those excited electrons are replaced by splitting a molecule of water, which releases oxygen.
The electron transport chain releases energy, which is used to make ATP
Produces NADPH by transferring excited electrons and hydrogen ions to NADP+.
Light Reactions Photosystem I and Photosystem IISUMMARY: In the light reactions, electron transport chains generate ATP, NADPH, & O2
Two connected photosystems collect photons of light and transfer the energy to chlorophyll electrons
The excited electrons are passed from the primary electron acceptor to electron transport chains
The light reactions convert light energy to the chemical energy of ATP and NADPH
The Light Dependent Reactions
The production of ATP in photosynthesisThylakoid compartment (high H+)Thylakoid membraneStroma (low H+)LightAntenna moleculesLightELECTRON TRANSPORT CHAINPHOTOSYSTEM IIPHOTOSYSTEM IATP SYNTHASE
Calvin CycleCalled a cycle because the starting material, RuBP, is regenerated.
Uses carbon from carbon dioxide, the energy from ATP, and high energy electrons and hydrogen ions from NADPH to make a small sugar named G3P.
The plant uses G3P to make glucose and other organic molecules.
Overall input:CO2, ATP, NADPH
Overall output: Glucose
Review: Photosynthesis uses light energy to make food moleculesLight reactions use water and produce oxygen.
The Calvin Cycle uses ATP and NADPH created in the the light reactions to convert carbon dioxide to glucose.
LightChloroplastPhotosystem II Electron transport chains Photosystem ICALVIN CYCLEStromaElectronsLIGHT REACTIONSCALVIN CYCLECellular respirationCelluloseStarchOther organic compounds
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Photosynthesis Cellular Respiration comparison