Photosynthesis

• What is photosynthesis?

  The process plants use to synthesize glucose
• How is light energy used in photosynthesis?

  It is converted into chemical energy
• Where does photosynthesis take place?

  Within chloroplasts in leaf palisade cells
• What pigment is involved in photosynthesis?

  Chlorophyll absorbs light energy
• What is the word equation for photosynthesis?

  Carbon dioxide + water → glucose + oxygen
• What is the symbol equation for photosynthesis?

  6CO2 + 6H2O → C6H12O6 + 6O2
• Is photosynthesis an endothermic or exothermic reaction?

  It is an endothermic reaction
• Why is photosynthesis considered endothermic?

  Energy is transferred from the environment
• How can you demonstrate that a plant gives off oxygen during photosynthesis?

  Collect gas bubbles from a water plant
• What happens to a glowing splint in the presence of oxygen?

  It relights when exposed to oxygen
• What are the adaptations of leaves that maximize photosynthesis?

  • Broad leaves for maximum surface area
  • Thin leaves for short diffusion distance
  • Chlorophyll to trap light energy
  • Veins for water transport and product removal
  • Air spaces for gas exchange
  • Guard cells to control stomata opening
• What are the four main factors affecting the rate of photosynthesis?

  Temperature, light intensity, CO2 concentration, chlorophyll
• How does temperature affect the rate of photosynthesis?

  Increased temperature raises the rate until enzymes denature
• What happens to the rate of photosynthesis at high temperatures?

  The rate decreases as enzymes become denatured
• How does light intensity affect the rate of photosynthesis?

  Increased light intensity raises the rate until limited
• How does carbon dioxide concentration affect the rate of photosynthesis?

  Increased CO2 concentration raises the rate until limited
• What effect does a lack of chlorophyll have on photosynthesis?

  It decreases the rate of photosynthesis
• What is a limiting factor in photosynthesis?

  An environmental factor that restricts the rate
• How can you calculate the rate of photosynthesis using oxygen production?

  Measure the distance moved by a gas bubble
• How can farmers increase profits using knowledge of limiting factors?

  • Control temperature
  • Adjust light intensity
  • Manage CO2 concentration
  • Achieve fastest rate of photosynthesis
  • Increase crop yield
• What law describes the relationship between light distance and intensity?

  Inverse square law
• What is the relationship described by the inverse square law?

  Light intensity ∝ 1 / distance²
• What are five uses of glucose produced during photosynthesis?

  • Respiration
  • Starch for storage
  • Cellulose for strength
  • Amino acids and protein synthesis
  • Lipids for energy storage in seeds