topic 4- bioenergetics

• What is photosynthesis?

  Process by which plants make glucose
• What type of reaction is photosynthesis?

  It 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?

  Rate increases until enzymes denature
• How does light intensity affect photosynthesis?

  Higher light intensity increases the rate
• What is the effect of carbon dioxide concentration on photosynthesis?

  Increased concentration raises the reaction rate

  
• Why is chlorophyll important for photosynthesis?

  It converts light energy to food
• What happens if chlorophyll levels are reduced?

  The rate of photosynthesis decreases
• How can you measure the rate of photosynthesis in an experiment?

  • Measure oxygen production
  • Use pondweed in water
  • Seal with a bung and capillary tube
  • Measure bubble distance to calculate volume
• What is the purpose of controlling variables in a photosynthesis experiment?

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

  An environmental condition restricting the rate
• How can you identify a graph with one limiting factor?

  It has one line that levels off
• What does a graph with two lines represent?

  Two limiting factors in two experiments
• What does light intensity measure in photosynthesis experiments?

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

  Light intensity is inversely proportional to distance squared
• If a lamp is 2 meters away, what is the light intensity?

  It 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 cell walls
  5. Combined with nitrates to form amino acids
• What is respiration?

  Process of transferring energy from glucose
• Is respiration an exothermic or endothermic process?

  It is an exothermic process
• What are the two types of respiration?

  Aerobic and anaerobic respiration
• What happens during aerobic respiration?

  It uses oxygen and yields the most energy
• Where do most aerobic respiration 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?

  It occurs without enough oxygen
• What is produced in anaerobic respiration in animals?

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

  Ethanol and carbon dioxide are produced
• What is oxygen debt?

  Extra oxygen needed after exercise
• What happens to lactic acid after exercise?

  It is transported to the liver for conversion
• What is metabolism?

  • Sum of all reactions in a cell or body
  • Energy from respiration used to make new molecules
  • Controlled by enzymes