To do this, pieces of liver, apple, potato and chicken breast were tested, with solutions of differing pH level being used. For the enzyme catalase, the optimum pH is 7.0, a neutral solution.2 Furthermore, the influence of surface area was investigated by using both cubed and crushed versions of the tissue being tested. Increasing the surface area of a particular cell type increases the amount of available active sites that an enzyme can bind to. The greater the opportunity of binding, the greater the reaction rate. .
Hypotheses.
1. The reaction rate of the enzyme, catalase, will be greatest at its optimum pH of 7.
2. Increasing the surface area by crushing each cell type will increase the catalase activity.
3. The liver, and chicken breast animal cells will have greater catalase activity than the potato, and apple plant cells.
Method.
Materials.
Hydrogen Peroxide of pH 3, 7 & 10.
1 Liver (Sheep).
1 Chicken Breast.
1 Potato.
1 Apple.
Knife .
Forceps.
3x Measuring Cylinder (250mL).
Detergent.
Cutting Board.
Stopwatch.
Procedure.
1. Cut six cubes of liver to dimensions of 1cm x 1cm x 1cm. .
2. Transfer 9mL of H2O2 into three different 150mL measuring cylinders, each one containing a different pH solution (3, 7, 10). .
3. Add two drops of detergent to each cylinder and swirl to mix. .
4. Using the forceps, place one cube of liver into the measuring cylinder and record the total height of froth after two minutes.
5. Repeat this procedure; however crush each piece of liver this time to increase surface area.
6. Repeat all above steps, but using cubes of apple, potato and chicken breast.
Variables.
Independent Variables .
Hypothesis 1 – pH.
Hypothesis 2 – Surface area.
Hypothesis 3 – Type of tissue.
Dependent Variables: .
Reaction rate, resulting temperature.
Controlled Factors.
Volume of detergent, initial temperature (16, time, amount of material in each test tube.
Discussion.
This investigation was designed to determine the effect and presence of the enzyme catalase.