Respiration

• What is the chemical equation for aerobic respiration?

  C₆H₁₂O₆ + 6O₂ -> 6H₂O + 6C0₂
• How are the mitochondria adapted for respiration?

  They have a folded inner membrane providing a large surface area for the enzymes involved
• Why is respiration needed? (4)

  1) Energy for 'building activities' e.g., building molecules from smaller ones

  2) Contraction of muscles

  3) Maintaining a constant internal body temperature

  4) Moving mineral ions from the soil into root hair cells in plants and converting sugars and other nutrients into amino acids
• What do muscles store glucose as and what is it used for?

  Glycogen and it used to convert rapidly back to glucose to use during exercise
• What are the body's responses to exercise? (3)

  1) Heart rate increases and arteries widen increasing the flow of oxygenated blood to exercising muscles as well as increasing the rate of which carbon dioxide is removed from the muscles

  2) Breathing rate increases and deepens bringing in more air so the rate at which oxygen is brought into the body and is picked up by red blood cells increases as well as carbon dioxide being removed

  3) Glycogen stored in the muscles converted back to glucose for cellular respiration
• When is anaerobic respiration used?

  When the blood cannot supply oxygen to the muscles fast enough
• What is the word equation for anaerobic respiration?

  Glucose -> Lactic acid
• What is oxygen debt?

  The amount of oxygen needed to oxidise lactic acid to carbon dioxide and water
• What is the word equation for oxygen debt repayment?

  Lactic acid + Oxygen -> Carbon dioxide + Water
• What is the word equation for anaerobic respiration in plants?

  Glucose + Ethanol -> Carbon dioxide
• What is metabolism?

  Sum of all chemical reactions in the body
• What are some examples of metabolic reactions? (5)

  1) Conversion of glucose to starch, glycogen, and cellulose

  2) Formation of lipid molecules from a molecule of glycerol

  3) Reactions for respiration

  4) Reactions of photosynthesis

  5) Breakdown of excess proteins in the liver to from urea for excretion in the urine by the kidneys
• What are the roles of the liver? ()3)

  1) Detoxifying poisonous substances e.g., lactic acid

  2) Passing the breakdown products into the blood so they can be excreted in the urine via the kidneys

  3) Breaking down old, worn out blood cells and storing the iron until they need to synthesise more blood cells
• How does the liver remove lactic acid?

  Blood flowing through the muscles transports lactic acid to the liver where it is converted back to glucose. Oxygen debt is fully repaid when all the converted glucose is completely broken down in aerobic respiration