AQA A Level Biology复习笔记5.3.2 Photosynthetic Products

Photosynthetic Products

 

  • The process of photosynthesis transfers light energy to chemical energy in biological molecules
  • In ecosystems where sunlight and water is available, the process of photosynthesis enables plants to synthesise organic compounds (glucose and other sugars) from carbon dioxide
  • Most of these sugars synthesised by plants are used by the plant as respiratory substrates
    • A respiratory substrate is a molecule (such as glucose) that can be used in respiration, to release energy for growth

     

  • The remaining sugars (not used in respiration) are used to make other groups of biological molecules, such as:
    • Starch - a complex carbohydrate molecule (formed from many glucose molecules) that acts as a short-term energy storage molecule
    • Cellulose - another complex carbohydrate molecule (also formed from many glucose molecules) that acts as a structural component of plant cell walls
    • Lipids - plant cells can convert the sugars produced during photosynthesis into lipids, which act as another type of (longer-term) energy storage molecule
    • Proteins - plant cells can also combine the sugars produced during photosynthesis with nitrates to make amino acids, which can then be used to produce proteins

     

  • These different groups of biological molecules (all formed from the sugars synthesised by plants during photosynthesis) make up the biomass of the plants
    • The biomass is the mass of living material
    • The biomass can also be thought of as the chemical energy that is stored within the plant

     

Photosynthetic-product-uses-1Photosynthetic-product-uses-2Photosynthetic-product-uses-3

The sugars synthesised during photosynthesis can be used in respiration or the creation of other biological molecules needed by plants

 

 

转载自savemyexams

更多Alevel课程
翰林国际教育资讯二维码