respiration

• Why do organisms need energy?

  For chemical reactions, movement, and growth
• What is the role of energy in muscle contraction?

  Energy is needed for muscles to contract
• What is respiration in cells?

  A chemical reaction that releases energy
• What is aerobic respiration?

  It uses oxygen to release energy in cells
• What is the equation for aerobic respiration?

  6O₂ + C₆H₁₂O₆ → 6CO₂ + 6H₂O (+energy)
• Why is aerobic respiration considered an exothermic reaction?

  It releases energy to its surroundings
• What do muscles need during exercise?

  More glucose and oxygen for respiration
• How does the body respond to increased exercise?

  Breathing rate and heart rate increase
• What is anaerobic respiration?

  Glucose breakdown without oxygen
• What is produced during anaerobic respiration in animals?

  Lactic acid and energy
• What is the energy released from anaerobic respiration?

  150 kJ mol⁻¹
• What happens to lactic acid after exercise?

  It is converted back to glucose in the liver
• How does anaerobic respiration differ from aerobic respiration?

  Anaerobic does not use oxygen, aerobic does
• What is fermentation in yeast?

  Anaerobic respiration producing ethanol and carbon dioxide
• What is the equation for fermentation in yeast?

  C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (+energy)
• What are the main differences between aerobic and anaerobic respiration?

  • Aerobic uses oxygen; anaerobic does not
  • Aerobic produces carbon dioxide and water; anaerobic produces lactic acid or ethanol
  • Aerobic releases a large amount of energy; anaerobic releases a small amount
• What is metabolism?

  • The sum of all reactions in a cell/body
  • Includes metabolic waste that needs removal
  • Metabolic rate is the speed of chemical reactions
• What is glycogen?

  A carbohydrate store in animals
• What happens to glycogen during exercise?

  It is converted to glucose for energy
• What is oxygen debt?

  Extra oxygen needed after exercise to process lactic acid
• What is the effect of lactic acid buildup in muscles?

  It causes muscle fatigue and inefficient contraction
• What is the metabolic waste?

  Substances produced that may be toxic
• What is the metabolic rate?

  The speed at which chemical reactions occur