AQA (OCR Syllabus)

• What is photosynthesis?

  Photosynthesis is the process by which plants make glucose from sunlight.
• What type of reaction is photosynthesis?

  Photosynthesis is an endothermic reaction.
• What is the equation for photosynthesis?

  Light + carbon dioxide + water → glucose + oxygen.

  
• What is the chemical symbol for carbon dioxide?

  CO₂
• What is the chemical symbol for water?

  H₂O
• What is the chemical symbol for oxygen?

  O₂
• What is the chemical formula for glucose?

  C₆H₁₂O₆
• What factors affect the rate of photosynthesis?

  • Temperature
  • Light intensity
  • Carbon dioxide concentration
  • Amount of chlorophyll

  
• How does temperature affect the rate of photosynthesis?

  As temperature increases, the rate of photosynthesis increases until enzymes denature.
• What happens to the rate of photosynthesis when light intensity increases?

  The rate of photosynthesis generally increases with higher light intensity.

  
• How does carbon dioxide concentration affect photosynthesis?

  As carbon dioxide concentration increases, the rate of photosynthesis increases.

  
• What role does chlorophyll play in photosynthesis?

  Chlorophyll converts light energy to food for the plant.
• What is a limiting factor in photosynthesis?

  A limiting factor is an environmental condition that restricts the rate of photosynthesis.
• How can the rate of photosynthesis be measured experimentally?

  By measuring the oxygen production of a plant.
• Describe the experimental setup to measure the rate of photosynthesis using pondweed.

  • Place pondweed in a test tube with water.
  • Seal the top with a bung and attach a capillary tube.
  • Position a lamp at a measured distance.
  • Measure the distance the oxygen bubble moves in the capillary tube.
• What is the effect of temperature on the rate of photosynthesis in an experiment?

  Temperature can be controlled using a water bath.
• What does it mean if a graph levels off in relation to limiting factors?

  It indicates that a limiting factor is restricting the rate of photosynthesis.
• How is light intensity measured in experiments related to photosynthesis?

  Light intensity is measured in lux.

  
• What is the inverse square law in relation to light intensity?

  Light intensity is inversely proportional to the square of the distance from the light source.
• If a lamp is 2 meters away from a plant, what is the light intensity compared to its original value?

  The light intensity is a quarter of its original value.
• What are the uses of glucose produced in photosynthesis?

  1. For respiration
  2. Converted into insoluble starch for storage
  3. To produce fat or oil for storage
  4. To produce cellulose for cell walls
  5. Combined with nitrates to form amino acids
• What is respiration?

  Respiration is the process of transferring energy from glucose.
• What type of reaction is respiration?

  Respiration is an exothermic reaction.
• What are the two types of respiration?

  Aerobic respiration and anaerobic respiration.
• What happens during aerobic respiration?

  Aerobic respiration uses oxygen and yields the most energy.
• What is the equation for aerobic respiration?

  C₆H₁₂O₆ + O₂ → CO₂ + H₂O.
• What occurs during anaerobic respiration in animals?

  Anaerobic respiration produces lactic acid from glucose.
• What is fermentation in plants and yeast cells?

  Fermentation produces ethanol and carbon dioxide from glucose.
• What is oxygen debt?

  Oxygen debt is the amount of extra oxygen needed after exercise to break down lactic acid.
• How is lactic acid transported after exercise?

  Lactic acid is transported to the liver where it is converted back to glucose.
• What is metabolism?

  Metabolism is the sum of all the reactions in a cell or the body.
• What are examples of metabolic reactions?

  1. Conversion of glucose to starch, glycogen, and cellulose
  2. Formation of lipids from glycerol and fatty acids
  3. Formation of amino acids from glucose and nitrate ions
  4. Reactions in respiration
  5. Formation of urea from protein breakdown