Bioenergetics

• What is the process that plants use to trap light energy?

  Photosynthesis
• What type of reaction is photosynthesis?

  Endothermic reaction
• Where does photosynthesis take place in a plant?

  In the leaves
• What green chemical in leaves absorbs light energy?

  Chlorophyll
• What are the inputs for photosynthesis?

  Carbon dioxide and water
• What is produced as a byproduct of photosynthesis?

  Oxygen
• What is the word equation for photosynthesis?

  Carbon dioxide + water → glucose + oxygen
• What happens to the rate of photosynthesis when light intensity is increased?

  The rate of photosynthesis increases
• What does it mean if light intensity is a limiting factor?

  Photosynthesis is not as fast as possible
• What happens when light intensity is increased beyond a certain point?

  The rate of photosynthesis levels off
• What is the limiting factor when light intensity is no longer increasing the rate of photosynthesis?

  Carbon dioxide level
• What happens to the rate of photosynthesis when carbon dioxide levels are increased?

  The rate of photosynthesis increases
• What does it indicate when carbon dioxide is a limiting factor?

  Photosynthesis is not as fast as possible
• What other factors can affect the rate of photosynthesis?

  Amount of chlorophyll and temperature
• How does the amount of chlorophyll affect photosynthesis?

  Less chlorophyll means lower photosynthesis rate
• How does temperature affect the enzymes involved in photosynthesis?

  Higher temperature increases enzyme activity
• What happens to enzymes at very high temperatures?

  They denature and activity falls
• What are the stages of photosynthesis?

  1. Light absorption by chlorophyll
  2. Conversion of carbon dioxide and water into glucose
  3. Production of oxygen as a byproduct
• What factors affect the rate of photosynthesis?

  • Light intensity
  • Carbon dioxide level
  • Amount of chlorophyll
  • Temperature
• What is produced during photosynthesis?

  Glucose and oxygen
• How is glucose produced in photosynthesis?

  By chemically reacting carbon dioxide and water using light energy
• What is the first use of glucose produced in photosynthesis?

  To release energy in respiration
• Where does respiration take place in plant cells?

  In the mitochondria
• When does photosynthesis produce glucose?

  Only during the day when there's light
• What is the second use of glucose produced by photosynthesis?

  To produce the insoluble storage molecule starch
• How can starch be converted back to glucose?

  When the plant needs it, such as at night
• What do plants convert glucose into for energy storage?

  Fats and oils
• What is cellulose made from?

  Glucose produced by photosynthesis
• What is the final use of glucose produced in photosynthesis?

  To produce amino acids
• What do plants need to absorb to make amino acids from glucose?

  Nitrate ions from the soil
• What are the main uses of glucose produced in photosynthesis?

  • Release energy in respiration
  • Produce insoluble storage molecule starch
  • Convert to fats and oils for energy storage
  • Produce cellulose for cell walls
  • Synthesize amino acids for proteins
• What is the word equation for photosynthesis?

  • Carbon dioxide + Water
  • Light energy
  • Produces Glucose + Oxygen
• What equipment is used to start the experiment?

  • Boiling tube
  • LED light source
  • Sodium hydrogen carbonate solution
  • Pond weed
• Why is an LED light source preferred in the experiment?

  It doesn't release much heat
• What should be placed between a normal light bulb and the boiling tube?

  A beaker of water
• What does sodium hydrogen carbonate solution release?

  Carbon dioxide
• What is the purpose of the pond weed in the experiment?

  To produce oxygen through photosynthesis
• How long should the pond weed acclimatize in the boiling tube?

  Five minutes
• What do we count to measure the rate of photosynthesis?

  The number of bubbles produced
• How many times should the bubble count be repeated?

  Two more times