Photosynthesis

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  • Created by: Sophie
  • Created on: 07-04-13 11:04

Photosynthesis (basics)

  • produces the plants food
  • happens inside chloroplasts-contain chlorophyll which abosbs sunlight, uses suns energy to convert carbon dioxide (from air) and water (from soil) into glucose and oxygen (by-product)

(http://www.bbc.co.uk/schools/gcsebitesize/science/images/add_aqa_equa_lighten.gif)

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Plant Organs

  • plant organs include-stems, roots and leaves
  • organs are made of tissue
  • leaves are made of:
    • mesophyll tissue-where most photosynthesis occurs
    • xylem and phloem-transport water, mineral ions & surcrose around plant
    • epidermal tissue-covers plant
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Rate of Photosynthesis

  • factors-intensity of light, volume of CO2, temperature
  • limiting factor-something that is stopping photosynthesis from happening faster
  • depends on environmeantal conditions:
    • night-light is limiting factor
    • winter-temperature
  • warm enough & bright enough-CO2 limiting factor

rate of photosynthesis plotted against light intensity. the rate begins to slow as the light intensity continues to increase (http://www.bbc.co.uk/schools/gcsebitesize/science/images/photosyn_1.gif)rate of photosynthesis plotted against carbon dioxide concentration. the rate begins to slow as the carbon dioxide concentration continues to increase (http://www.bbc.co.uk/schools/gcsebitesize/science/images/photosyn_2.gif)rate of photosynthesis plotted against temperature. the rate begins to slow as the temperature continues to increase (http://www.bbc.co.uk/schools/gcsebitesize/science/images/photosyn_3.gif)

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How plants use glucose

  • respiration-releases energy during resperation, enables it to convert rest of the
  • glucose into useful substances for building cells and growing
  • making cell walls-converted into cellulose for making strong cell walls
  • making proteins-combined with nitrate ions to make amino acids
  • stored in seeds- turned into lipids for stroing in seeds-we get marg and cooking oil from sunflower seeds
  • stored as starch-turned into starch, stored in roots, stem and leaves, use when photosynthesis isnt happening, insoluble so best for stroing

(http://www.belladonnakillz.com/img2.jpg)(http://www.nature.com/scitable/content/ne0000/ne0000/ne0000/ne0000/17387034/LL_11model_picglucose_kac.jpg)

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