Aim: To inspect the effects of the pH on enzymes.
100 cm³ Beaker
3 – 5cm³ Syringes
2 Test Tube Racks with 8 Test Tubes
Dropping bottle of detergent
400cm³ Hydrogen Peroxide
200cm³ Liver Catalase Solution
100cm³ of following Buffer Solution – pH5 pH7 pH9 pH11
The materials were collected. The test tube rack one with 4 test tubes had been labelled A to D. The 2cm³ of each buffer solution had been inserted to test tubes A to D. 3cm³ of hydrogen peroxided was introduced to the tubes then a few drops of detergent had been included to the tubes A to D. We then used test tube rack two with 4 test tubes and labelled them 1 to 4. The 2cm³ of catalase solution had been added to the test tubes labelled 1 to 4. All the test tubes were then placed in the water bath for 5 minutes at 30ºc. The contents inside test tubes 1 to 4 had been added to test tubes A to D. After the enzyme reaction begun we measured the height of the froth in test tubes A to D. The table was prepared and the results had been jotted down. We also repeated the experiment for reliable results.
Foam Measured 1st Attempt
Foam Measured 2nd Attempt
The results above show that pH 7 had the highest average foam height. The enzyme is working its best as pH7 is the optimum pH for the enzyme.
Overall the experiment worked well however there might have been a few minor errors for example the amount of detergent dropped into the test tubes could have changed the results and also the pH labels might have been labelled wrong. Another error could have been poor timing, the test tubes being in the water bath for too long could have altered the results.
Graph: The Height of Foam Measured vs pH