Respiration

• What is aerobic respiration?

  An exothermic reaction in which glucose reacts with oxygen to release energy which binds to cells
• What is the symbol equation for aerobic respiration?

  C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)
• What is the word equation for aerobic respiration?

  Glucose + Oxygen → Carbon Dioxide + Water + Energy
• Where does aerobic respiration occur?

  Mitochondria
• Why do organisms require the energy released by respiration?

  Synthesis of larger molecules

  Muscle contraction

  Maintenance of body temperature

  Active transport
• What is anaerobic respiration?

  An exothermic reaction in which glucose is broken down to release energy in the absence of oxygen.
• What is the equation for anaerobic respiration in animals?

  Glucose → Lactic Acid
• Why is anaerobic respiration less efficent then aerobic?

  Glucose is not completely broken down, so less energy is transferred.
• Why can anerobic respiration lead to muscle fatigue?

  Lactic acid builds up in muscles preventing contraction
• What is oxygen debt?

  The amount of oxygen required to convert lactic acid back into glucose after anaerobic respiration.
• What is fermentation?

  A type of anaerobic respiration that occurs in yeast cells.
• What is the equation of fermentation?

  Glucose → Ethanol + Carbon Dioxide
• Why is the fermentation reaction important?

  Used the production of bread and alcohol.
• What are the differences between aerobic respiration?

  Aerobic respiration requires oxygen; anaerobic does not.

  Aerobic produces CO₂ and water; anaerobic produces lactic acid or ethanol + CO₂

  Aerobic transfers a greater amount of energy.
• How do muscles store glucose?

  Glycogen
• What changes take place when musclar activity increases in the body?

  Heart rate increases and arteries dilate; increases flow of oxygenated blood to muscles.

  Breathing rates increase and breathing is deeper - increases the rate of gaseous exchange

  Stored glycogen can be converted in glucose.
• How is lactic acid transported away from the muscles?

  Blood flow through the muscles transport lactic acid to the liver, where it is oxidised back to glucose.
• What is metabolism?

  The sum of all reactions that occur in an organism.
• How do cells use the energy transferred by respiration?

  Carry out enzyme controlled activites which lead to the synthesis of new molecules.
• Give examples of metabolic reactions.

  • Glucose into starch/glycogen/cellulose
  • Glycerol and fatty acids into lipids
  • Glucose and nitrate
  • Photosynthesis
  • Respiration
  • Breakdown of excess proteins into urea