12. Respiration

• Define aerobic respiration as the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy

• State the word equation for aerobic respiration as glucose + oxygen → carbon dioxide + water

• Investigate the uptake of oxygen by respiring organisms, such as arthropods and germinating seeds

• State the balanced chemical equation

for aerobic respiration as C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

• Investigate the effect of temperature on the rate of respiration of germinating seeds

• Define anaerobic respiration as the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen

• State the word equations for anaerobic anaerobic respiration in muscles during vigorous exercise (glucose → lactic acid) and in microorganism yeast (glucose → alcohol + carbon dioxide)

• State the balanced chemical equation for respiration in muscles during vigorous exercise

• State that anaerobic respiration releases much less energy per glucose molecule than aerobic respiration

• State the balanced chemical equation for anaerobic respiration in the microorganism yeast as C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂

• State that lactic acid builds up in muscles and blood during vigorous exercise causing an oxygen debt

• Outline how the oxygen debt is removed during recovery, limited to:

– aerobic respiration of lactic acid in the liver

– continuation, after exercise, of fast heart rate to transport lactic acid in blood from muscles to the liver

– continuation, after exercise, of deeper breathing supplying oxygen for aerobic respiration of lactic acid