Bioenergetics

• 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.
• How is energy transferred in photosynthesis?

  Energy is transferred from the environment to the chloroplasts by light.
• What is the equation for photosynthesis?

  Carbon dioxide + water → glucose + oxygen.

  
• What is the chemical formula for glucose?

  C​6​H​12​O​6
• What factors affect the rate of photosynthesis?

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

  
• How does temperature affect the rate of photosynthesis?

  With an increase in temperature, the rate of photosynthesis increases until enzymes begin to denature.
• What happens to enzymes at high temperatures during photosynthesis?

  Enzymes begin to denature, causing the rate of reaction to decrease.
• How does light intensity affect the rate of photosynthesis?

  The higher the light intensity, the faster the rate of the reaction for most plants.
• What is the effect of carbon dioxide concentration on photosynthesis?

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

  
• Why is chlorophyll essential for photosynthesis?

  Chlorophyll converts light energy to food for the plant.
• What happens if chlorophyll levels are reduced?

  The rate of photosynthesis would decrease.
• How can you measure the rate of photosynthesis in an experiment?

  • Measure oxygen production of a plant.
  • Use pondweed in a test tube with water.
  • Seal the top with a bung and use a capillary tube.
  • Measure the distance the oxygen bubble moves.
• What is a limiting factor in photosynthesis?

  A limiting factor is an environmental condition that restricts the rate of photosynthesis at low levels.
• How can you identify a graph with one limiting factor?

  A graph with one limiting factor has one line that levels off.
• What does a graph with two lines represent in terms of limiting factors?

  A graph with two lines represents two limiting factors in two experiments.
• How is light intensity measured in experiments?

  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.
• What are the uses of glucose produced from photosynthesis?

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

  Respiration is the process of transferring energy from glucose for living processes.
• Is respiration an exothermic or endothermic process?

  Respiration is an exothermic process.
• 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.
• Where do most reactions of aerobic respiration occur?

  Most reactions occur in the mitochondria.
• What is the equation for aerobic respiration?

  C​6​H​12​O​6​ + O​2​ → CO​2​ + H​2​O
• What occurs during anaerobic respiration?

  Anaerobic respiration occurs when there is not enough oxygen and yields less energy.
• What is lactic acid and when is it produced?

  Lactic acid is produced during anaerobic respiration in animals.
• What is fermentation in plants and yeast cells?

  Fermentation is the anaerobic respiration process that produces ethanol and carbon dioxide.
• What is oxygen debt?

  Oxygen debt is the amount of extra oxygen needed after exercise to break down lactic acid.
• What happens to lactic acid 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. Glucose to starch, glycogen, and cellulose
  2. Glycerol and fatty acids forming lipids
  3. Glucose and nitrate ions forming amino acids
  4. Reactions in respiration
  5. Urea formation from protein breakdown