Investigating the Effects of Exercise on Breathing

Question 1

what does this investigation investigate?

Answer 1

• it compares the content of inhaled and exhaled air, using a T-tube arrangement going from a mouthpiece into two conical flasks or boiling tubes
• the inhaled and exhaled air bubbles through the indicator as the student breathes in and out

Question 2

what colour does limewater go with inhaled and exhaled air?

Answer 2

• inhaled = stays colourless
• exhaled = turns milking white

Question 3

what colour does hydrogen carbonate indicator go with inhaled and exhaled air?

Answer 3

• inhaled = stays red
• exhaled = turns yellow

Question 4

effect of exercise on breathing rate method

Answer 4

• you easily compare breathing rates before and after exercise by watching and counting the number of breaths someone takes in 1 minute (or 30 seconds) at rest
• then ask your subject to to exercise - count the number of breaths they take in the first minute after exercise

Question 5

why does breathing rate increase during exercise?

Answer 5

• during exercise our breathing rate increases, as well as depth of each breath
• this is in response to the increases concentration of carbon dioxide in the blood
• because our breathing rate increases, we excrete carbon dioxide more rapidly
• oxygen can also diffuse into the blood at a faster rate (as there is a higher concentration gradient)
• this along with an increase in heart rate, supplies more oxygen to the muscles for aerobic respiration
• our muscles may respire anaerobically during exercise, if this happens our breathing rate will remain high after exercise, supplying the extra oxygen need to oxidise the lactic acid