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 symbol for carbon dioxide?

  The chemical symbol for carbon dioxide is CO₂.
• What is the chemical symbol for water?

  The chemical symbol for water is H₂O.
• What is the chemical symbol for oxygen?

  The chemical symbol for oxygen is O₂.
• What is the chemical symbol for glucose?

  The chemical symbol for glucose is C₆H₁₂O₆.
• What factors affect the rate of photosynthesis?

  The rate of photosynthesis is affected by temperature, light intensity, carbon dioxide concentration, and 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 at high temperatures, causing the rate of reaction to decrease.
• How does light intensity affect the rate of photosynthesis?

  For most plants, the higher the light intensity, the faster the rate of the reaction.
• How does carbon dioxide concentration affect the rate of photosynthesis?

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

  
• What role does chlorophyll play in photosynthesis?

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

  If chlorophyll levels are reduced, the rate of photosynthesis would decrease.
• How can the rate of photosynthesis be measured experimentally?

  • Measure oxygen production of a plant.
  • Use pondweed in a test tube with water.
  • Seal the top with a bung and connect a capillary tube.
  • Place a lamp at a measured distance.
  • Measure the distance the oxygen bubble moves to calculate volume.
• What variables can be changed in the photosynthesis experiment?

  Variables include temperature, time the pondweed is left, and light intensity.
• Why is it important to control all factors in a photosynthesis experiment?

  It is important to control all factors except the independent variable to ensure a valid experiment.
• What is a limiting factor in photosynthesis?

  A limiting factor is an environmental condition that restricts any increase in the rate of photosynthesis.
• How can a graph show limiting factors in photosynthesis?

  A graph shows one limiting factor if it has one line that levels off, with the factor on the horizontal axis and rate of photosynthesis on the vertical axis.
• What does a graph with two lines represent in photosynthesis experiments?

  A graph with two lines represents two limiting factors in two experiments.

  
• How is light intensity measured in photosynthesis experiments?

  Light intensity is measured in lux.

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

  The light intensity is inversely proportional to the square of the distance.
• 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 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.
• What type of reaction is respiration?

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

  The two types of respiration are aerobic and anaerobic respiration.
• What happens during exercise in relation to respiration?

  During exercise, more energy is needed, so respiration occurs faster and more oxygen is supplied to cells.
• How does the body respond to increased energy needs during exercise?

  The body responds by increasing heart rate, breathing rate, and breath volume.
• What is the equation for aerobic respiration?

  The equation for aerobic respiration is C₆H₁₂O₆ + O₂ → CO₂ + H₂O.
• What is anaerobic respiration?

  Anaerobic respiration occurs when there is not enough oxygen.
• What is produced during anaerobic respiration in animals?

  During anaerobic respiration in animals, lactic acid is produced.
• What is fermentation in plants and yeast cells?

  Fermentation in plants and yeast cells 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 processes are controlled by enzymes in metabolism?

  Processes include converting glucose to starch, forming lipids, and producing proteins.
• What is one example of a metabolic reaction?

  One example is glucose being converted to starch, glycogen, and cellulose.
• What is another example of a metabolic reaction?

  Another example is a glycerol molecule and three fatty acids forming a lipid molecule.