Chapter 6 - Plant Nutrition

• Photosynthesis


  Plants making food with the help of 'light' from the environment
• Photosynthesis


  Carbon dioxide + water → Glucose + oxygen
• Stomata


  • Opening and closing to allow gas exchange
• Chlorophyll


  • Absorbs sunlight for photosynthesis
• Glucose is used as nutrition
• Osmosis


  Diffusion of water through a semi-permeable membrane
• Xylem


  Transports water and nutrients upwards
• Phloem


  Transports glucose and other organic compounds throughout the plant
• Photosynthesis equation: 6CO₂ + 6H₂O → C₂H₁₂O₆ + 6O₂
• Types of leaves


  • Monocot
  • Dicot
• Dicot leaf

  • midrib
  • veins - xylem (water), phloem (nutrients)
  • petiole
  • lamina - broad, flat thin
  • tip
• Photosynthesis


  1. Carbon dioxide diffuses into leaf through stomata

  2. Glucose and oxygen diffuse out of leaf through stomata
• Glucose


  Forms fats, transported as sucrose, stored as starch
• Photosynthesis


  1. Glucose + nitrates → amino acids

  2. Glucose + magnesium → chlorophyll
• Glucose is used for respiration
• Very hot day


  Stomata closes to prevent water loss
• Stomata closing


  Prevents diffusion of CO₂ into leaf
• Limiting factors of photosynthesis


  Something in short supply in the environment that restricts the life process
• Increasing CO₂


  Increases photosynthesis
• Increasing temperature


  Increases photosynthesis (up to an optimum)
• Xylem vessel


  • Hollow, transports nutrients in one direction
• Vascular bundle


  • Contains xylem and phloem
• Veins


  • Transport nutrients
• Cuticle


  • Waterproof layer that prevents water loss
• Palisade cell


  • Rectangular, tightly packed with chloroplasts
• Spongy cell


  • Has air spaces and chloroplasts
• Guard cell


  • Opens and closes stomata
• Sucrose is transported to the roots and stored as starch or stored in fruit
• Translocation of sugars produced in photosynthesis occurs in two directions
• The roots are the main site of nutrient absorption.