Respiration: Practice Questions

• a.

  Lactic acid is converted into glycogen within the muscle cells to provide immediate energy.

• b.

  The depth of breathing decreases to allow for faster gas exchange in the alveoli.

• c.

  The heart rate decreases to conserve oxygen for the brain.

• d.

  Glycogen stored in the muscles is converted back to glucose and the breathing rate increases.

• a.

  Lactic acid builds up due to incomplete glucose breakdown, requiring oxygen later to be oxidised into carbon dioxide and water.

• b.

  Ethanol builds up in the muscle tissue, which must be converted back into glucose by the liver using oxygen.

• c.

  Carbon dioxide levels rise too high in the mitochondria, preventing the further breakdown of glycogen.

• d.

  The complete breakdown of glucose into lactic acid releases too much energy, causing the enzymes to denature.

• a.

  \( \text{lactic acid} + \text{carbon dioxide} \rightarrow \text{glucose} + \text{oxygen} \)

• b.

  \( \text{glucose} \rightarrow \text{lactic acid} + \text{energy} \)

• c.

  \( \text{glucose} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water} \)

• d.

  \( \text{lactic acid} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water} \)

• a.

  It takes place entirely within the mitochondria to maximize ATP production.

• b.

  It produces ethanol and carbon dioxide as the primary waste products.

• c.

  It transfers significantly more energy per glucose molecule than aerobic respiration.

• d.

  It results in an incomplete breakdown of glucose, which causes a build-up of lactic acid.

• a.The body needs to switch immediately to anaerobic respiration to remove carbon dioxide from the blood.
• b.The muscles require additional oxygen to convert glucose into glycogen for long-term storage.
• c.An oxygen debt needs to be repaid to oxidise the lactic acid to carbon dioxide and water.
• d.The high breathing rate is required to facilitate the transport of ethanol from the muscles to the liver.

Write your answer out first, then check it against the worked solution.