2.   Add about 10 mL 3% hydrogen peroxide to a small test-tube.
3.   Quickly add 5 mL catalase extract (from the potato pulp).
4.   Stopper the test-tube, swirl it once to mix the contents, and place the tubing
      leading from the stopper beneath an inverted, water-filled graduated cylinder.
      Record the time.
5.   Record the volume of gas produced each minute for 5 min. Record your data.
6.   Construct a graph that will allow you to record volume of gas produced on the
      y-axis and time on the x-axis. Label this Graph 1.

Effect of Temperature on Volume of Gas Produced
    1.   Add 10 mL catalase extract to a small test-tube.
    2.   Add 10 mL 3% hydrogen peroxide to a second small test-tube.
    3.   Place both test-tubes in a water bath for 5 min. Your teacher will specify the
          temperature for your water bath.
    4.   Remove both tubes, quickly pour 3% hydrogen peroxide into the catalase,
          stopper, and collect the gas produced as in the procedure above.
    5.   After 5 min, measure the amount of gas produced and record your data.

Effect of an Inhibitor on the Volume of Gas Produced
    1.   Place 10 mL catalase extract in a small test-tube.
    2.   Add 2 mL copper(II) sulfate solution to the tube.
    3.   Place 10 mL 3% hydrogen peroxide in a separate tube.
    4.   Place both tubes in a water bath at 20 °C for about 5 min.
    5.   Remove the tubes, add the 3% hydrogen peroxide to the catalase, shake to mix.
    6.   Quickly stopper the tube and collect the gas as you did above.
    7.   Measure the volume of gas produced after 5 min and record your data.
    8.   Thoroughly wash your hands before leaving the laboratory.

Data Analysis

    1.   According to the data you plotted on Graph 1, how does the volume of gas
          produced by the breakdown of hydrogen peroxide vary with time?
    2.   Your teacher will ask you to plot your data for temperature vs. volume of gas
          on a master graph along with the data from your classmates.
          According to the data plotted on the master graph, what is the effect of
          temperature on the rate of enzymatic action? At some point, did the
          volume of gas not increase as temperature increased? How can you account
          for this?
    3.   According to your data, what effect did adding an inhibitor [copper(II) ions]
          have on the rate of gas production? Did the production of gas cease completely?
          How can you account for this?
 

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