Photosynthesis

• • Takes place in chloroplasts
  • Is endothermic - energy is transferred from environment by light

  light

  carbon dioxide + water - - - - > glucose + oxygen
• Using Glucose:

  Plant uses glucose in 5 main ways:

  1. For respiration - transfers energy from glucose which allows plant to convert glucose into useful substances
  2. Making cellulose - for strong plant cell walls
  3. Making amino acids - glucose and nitrate ions make amino acids, which are made into proteins
  4. Stored as oils/fats - lipids for storing in seeds
  5. Stored as starch - stored in roots, stems, leaves
• Limiting factors:

  • Limiting factors of photosynthesis are: light, carbon dioxide concentration, temperature, chlorophyll
  • Chlorophyll is used to absorb light
  • Chlorophyll can be affected by diseases and lack of nutrients - lack of chlorophyll = lack of light absorbed
• Artificial conditions:

  • Greenhouse are used as they trap heat
  • Farmers supply artificial light after sun goes down
  • Farmers increase level of carbon dioxide in greenhouse e.g paraffin heater to heat which produces carbon dioxide
  • Greenhouse keeps free from pests and diseases - fertilisers can be added