Describe a method to find the rate of respiration in insect. (5 marks)

Set up the apparatus as shown, make sure that the apparatus in airtight. Sodium hydroxide in added into both test tubes to remove carbon dioxide produced by the

respiring insect and to have similar initial pressures in both testubes. Place the insect in one test tube and glass beads of equal mass in the other test tube. Dip the test tubes in a water bath to keep temperature constant. As temperature affects

enzyme activity by maintaining a constant temperature rate of respiration would remain constant throughout.

Measure the time taken for the fluid in the manometer to move a fixed distance. Rate of respiration = 1/ time taken Take repeat readings by adjusting the screw clip and letting air in.