Bioenergetics

• What is the setup for measuring oxygen production in plants?

  • Pondweed in a test tube with water
  • Sealed with a bung
  • Capillary tube with water attached to a syringe
  • Lamp placed at a measured distance
• What can be measured to calculate the rate of photosynthesis?

  Oxygen production of a plant
• What happens as the plant photosynthesizes in the experiment?

  Oxygen is produced, forming a gas bubble
• How is the volume of oxygen produced calculated in the experiment?

  By measuring the distance the bubble has moved
• What variables can be changed to observe their effect on photosynthesis?

  • Temperature (using a water bath)
  • Time the pondweed is left
  • Light intensity (varied by lamp distance)
• Why is it important to control all factors in the experiment?

  To ensure a valid experiment
• What is a limiting factor in photosynthesis?

  An environmental condition restricting photosynthesis
• What happens to the rate of photosynthesis when a limiting factor is low?

  It restricts any increase in the rate
• How can a graph indicate a limiting factor in photosynthesis?

  By showing a curve that levels off
• What does a graph with two lines represent in photosynthesis experiments?

  • Two limiting factors in two experiments
  • Increasing the factor on the horizontal axis
  • Carried out at two different environmental conditions
• What is the process by which plants make glucose from sunlight?

  Photosynthesis
• What type of reaction is photosynthesis?

  Endothermic reaction
• How is energy transferred to chloroplasts during photosynthesis?

  By light
• What is the equation for photosynthesis?

  • light + carbon dioxide + water → glucose + oxygen
• What is the process by which plants make glucose from sunlight?

  Photosynthesis
• What is the chemical symbol for carbon dioxide?

  CO​2
• What type of reaction is photosynthesis?

  Endothermic reaction
• What is the chemical formula for water?

  H​2O
• What is transferred from the environment to the chloroplasts during photosynthesis?

  Energy by light
• What is the chemical symbol for oxygen?

  O​2
• How does temperature affect the rate of photosynthesis?

  Increases rate until enzymes denature
• What happens to enzymes at high temperatures during photosynthesis?

  They begin to denature
• What is the equation for photosynthesis?

  light + carbon dioxide + water → glucose + oxygen
• How does carbon dioxide concentration affect photosynthesis?

  Increases rate as concentration increases
• What is the chemical symbol for carbon dioxide?

  CO​2
• What is the chemical formula for glucose?

  C​6H​12O​6
• What role does chlorophyll play in photosynthesis?

  Converts light energy to food
• How does temperature affect the rate of photosynthesis?

  Rate increases with temperature until enzymes denature
• What effect does magnesium deficiency have on chlorophyll levels?

  Reduces chlorophyll levels
• What happens to enzymes at high temperatures during photosynthesis?

  They begin to denature
• What is the consequence of reduced chlorophyll levels on photosynthesis?

  Decreases the rate of photosynthesis
• How does carbon dioxide concentration affect the rate of photosynthesis?

  Rate increases with higher carbon dioxide concentration
• What is chlorophyll's role in photosynthesis?

  Converts light energy to food for the plant
• What effect does a magnesium deficiency have on chlorophyll levels?

  Reduces chlorophyll levels
• What is the consequence of reduced chlorophyll levels on photosynthesis?

  Decreases the rate of photosynthesis
• What unit is light intensity measured in?

  Lux
• What does the graph indicate about light intensity as a limiting factor?

  50 lux limits photosynthesis compared to 100 lux
• How can farmers use knowledge of limiting factors?

  To enhance greenhouse conditions for growth
• What is the relationship described by inverse proportion?

  • One factor increases while another decreases
  • Example: Light intensity decreases with distance
• What does the inverse square law state about light intensity and distance?

  Light intensity is inversely proportional to the square of the distance