bioenergetics

• What is photosynthesis?

  Photosynthesis is the process by which plants make glucose from sunlight.
• How is energy transferred in photosynthesis?

  Energy is transferred from the environment to the chloroplasts by light.
• What type of reaction is photosynthesis?

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

  Carbon dioxide + water → glucose + oxygen.

  
• What is the chemical symbol for carbon dioxide?

  CO​2
• What is the chemical symbol for water?

  H​2​O
• What is the chemical symbol for oxygen?

  O​2
• 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.
• How does light intensity affect the rate of photosynthesis?

  The higher the light intensity, the faster the rate of the reaction for most plants.
• 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?

  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 use a capillary tube.
  • Measure the distance the oxygen bubble moves.
• What variables can be changed in the photosynthesis experiment?

  The temperature, time the pondweed is left, and light intensity can be changed.
• Why is it important to control all factors except the independent variable in an experiment?

  To ensure the experiment is valid.
• 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.
• What does a graph with two lines represent in photosynthesis experiments?

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

  
• What are the uses of glucose produced in photosynthesis?

  • To produce fat or oil for storage in seeds
  • To produce cellulose to strengthen cell walls
  • Combined with nitrates to form amino acids for proteins
• What is respiration?

  Respiration is the process of transferring energy from glucose so living processes can occur.
• What type of reaction is respiration?

  Respiration is an exothermic reaction.
• Can respiration occur aerobically and anaerobically?

  Yes, respiration can occur aerobically (with oxygen) or anaerobically (without oxygen).
• What happens during exercise in relation to respiration?

  More energy is needed for muscle contraction, so respiration occurs faster and more oxygen is supplied to cells.
• How does the heart rate change during exercise?

  The heart rate increases during exercise.
• How does the breathing rate change during exercise?

  The breathing rate increases during exercise.
• How does breath volume change during exercise?

  The breath volume increases during exercise.
• What is aerobic respiration?

  Aerobic respiration uses oxygen and yields the most energy.
• Where do most reactions of aerobic respiration occur?

  Most reactions of aerobic respiration 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 is anaerobic respiration?

  Anaerobic respiration occurs when there is not enough oxygen and does not yield as much energy as aerobic respiration.
• When is anaerobic respiration used?

  Anaerobic respiration is used as a last resort, for example during a sprint.
• What is produced in anaerobic respiration in animals?

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

  Ethanol and carbon dioxide are produced in anaerobic respiration in plants and yeast.
• What is oxygen debt?

  Oxygen debt is the amount of extra oxygen the body needs after exercise to react with 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 is the role of energy transferred in respiration?

  The energy transferred in respiration is used in the processes of metabolism to make new molecules.
• 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