Respiration: Bioenergetics: Biology: GCSE (9:1)

• Cellular respiration


  Process that releases energy by breaking down glucose and other food molecules
• Exothermic reaction


  A reaction that releases energy to its surroundings, usually in the form of heat

  
• Aerobic respiration


  Cell respiration which happens in the presence of oxygen in the mitochondria of the cell

  
• Word equation for aerobic respiration

  Glucose + oxygen -> carbon dioxide + water (+energy)

  
• Balanced chemical equation for aerobic respiration

  C6H12O6 + 6O2 -> 6CO2 + 6H2O

  
• Anaerobic respiration


  Cell respiration which happens in the absence of oxygen

  
• Word equation for anaerobic respiration

  Glucose -> lactic acid (+energy)

  
• Lactic acid


  A toxic waste product that is produced during anaerobic respiration in humans and can cause muscle fatigue

  
• Incomplete oxidation


  Occurs during anaerobic respiration causing a build up of lactic acid in the muscles
• Fermentation

  Anaerobic respiration in plant and yeast cells which produces ethanol and carbon dioxide

  
• Word equation for fermentation

  Glucose -> carbon dioxide + ethanol (+energy)

  
• Uses of fermentation

  The manufacture of bread and alcoholic drinks

  
• Liver


  Receives blood from the muscles with lactic acid and converts the lactic acid back into glucose

  
• Oxygen debt


  The amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid

  
• Effect of exercise

  Increased heart rate, breathing rate and breath volume to supply the muscles with more oxygen

  
• Organisms need energy for

  Movement, keeping warm and chemical reactions to make larger molecules
• Glucose (C6H12O6)


  The main reactant of respiration that is obtained from the digestion of carbohydrates

  
• Oxygen (O2)


  A molecule that is essential for the complete oxidation of glucose in aerobic respiration

  
• Carbon dioxide (CO2)


  A waste product of respiration that is removed from cells and the body via gas exchange

  
• Water (H2O)


  A byproduct of respiration that is either used or removed from the body typically during exhalation or urination