Bioenergetics

• What is the word equation for photosynthesis?

  Carbon dioxide + water → glucose + oxygen
• What type of reaction is photosynthesis?

  It is an endothermic reaction
• What supplies the energy needed for photosynthesis?

  Sunlight provides the necessary energy
• What chemical traps sunlight energy during photosynthesis?

  Chlorophyll traps sunlight energy
• What factors can change the rate of photosynthesis?

  • Temperature
  • Carbon dioxide concentration
  • Light intensity
  • Chlorophyll concentration
• What is the limiting factor in photosynthesis?

  The factor that stops the reaction going faster
• How does temperature affect the rate of photosynthesis?

  Higher temperatures increase the rate until enzymes are destroyed
• What happens to the rate of photosynthesis at 45°C?

  The rate drops to zero
• How does carbon dioxide concentration affect photosynthesis?

  Higher CO₂ concentration increases the rate
• What happens when CO₂ is no longer the limiting factor?

  Further increases have no effect on the rate
• How does light intensity affect the rate of photosynthesis?

  Higher light intensity increases the rate
• What happens when light is no longer the limiting factor?

  Further increases have no effect on the rate
• How does chlorophyll concentration affect photosynthesis?

  It does not vary in the short term
• What is produced during photosynthesis?

  Glucose and oxygen are produced
• How is glucose used by plants after photosynthesis?

  • Used in respiration for energy
  • Converted to insoluble starch for storage
  • Changed into fats or oils for storage
  • Used to form cellulose for cell walls
  • Used with nitrate ions to produce proteins
• What is the inverse square law in relation to light intensity?

  Doubling distance reduces light intensity by a quarter
• What is respiration in living organisms?

  It is an exothermic reaction releasing energy
• What is the equation for aerobic respiration?

  Glucose + oxygen → carbon dioxide + water
• What is produced during anaerobic respiration in animals?

  Lactic acid is produced
• What is fermentation in yeast cells?

  Anaerobic respiration producing ethanol and carbon dioxide
• What happens to lactic acid after exercise?

  It is transported to the liver for conversion
• What is oxygen debt?

  The extra oxygen needed after exercise
• What is metabolism?

  • Sum of all chemical reactions in a cell
  • Controlled by enzymes
  • Requires energy transfer from respiration
• What are the waste products of anaerobic respiration in plants?

  Alcohol and carbon dioxide are produced
• What do plants need to make proteins from glucose?

  Nitrate ions are needed
• Why do farmers control conditions in greenhouses?

  To increase the growth rate of crops
• What is the role of chlorophyll in photosynthesis?

  It traps sunlight energy for the reaction
• What happens to the energy from sunlight during photosynthesis?

  It is converted to chemical energy in glucose
• How do aerobic and anaerobic respiration differ in energy production?

  Aerobic produces more energy than anaerobic
• Why do muscles hurt during vigorous exercise?

  Due to the buildup of lactic acid
• What is the waste product of aerobic respiration?

  Carbon dioxide and water are produced
• What is the importance of respiration in living organisms?

  It provides energy for vital processes
• What is the role of enzymes in metabolism?

  They control chemical reactions in cells