investigate breathing practical

• how do you investigate effect of exercise on breathing?

  • sit still for 5 min
  • for 1 min - count number of breaths taken
  • now do 4 min of exercise - once stopped count breathes for a minute
  • repeat the steps and calculate average results for resting and after exercise
  • exercise = increase breathe rate - muscles respire more during exercise - supplied with more O2 and CO2 removed - breathing rate increased
• how do you investigate the release of carbon dioxide in your breath?

  • set up two boiling tubes and place same number of limewater in each
  • put mouth around mouthpiece and breathe in and out several times
  • as you breathe in - air from room drawn in through boiling tube A - air contains very little CO2 = limewater remains colourless
  • as you breathe out - air you exhale bubbles through limewater in boiling tube B. This air contains CO2 produced during respiration = limewater turns cloudy