activity of catalase.

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Aim: To investigate on the activity of catalase. Introduction Catalase, an enzyme found in many different tissues, catalyses the breakdown of hydrogen peroxide into water and oxygen. 2H₂O₂ → 2H₂O + O₂ Hydrogen peroxide is a toxic substance that can be formed during aerobic respiration and catalase removes this product. The activity of catalase can be measured by finding the rate of oxygen release from hydrogen peroxide. Minced potato provides a suitable source of catalase and the pH is varied in this experiment using citric acid-sodium phosphate buffer solutions at pH values of 4.4, 5.2, 6.5, 7.5 and 9. Hypothesis: As the value of pH increases, the amount of oxygen increases up to a point where the amount decreases. This is because the active site is denatured and the 3 dimensional figure is altered. Apparatus: • Citric acid-sodium phosphate buffer solutions of pH 4.4, 5.2, 6.5, 7.5 and 9 • Hydrogen peroxide solution • Potato • 10ml and 100ml measuring cylinder • Stopwatch • Stand and clamp • Water bucket • pH paper, pH meter and pH probe connected to data logger. • Cork borer • Large test tube • Rubber stopper and delivery tube Risk assessment/safety precautions Risk assessment Safety precautions Citric acid may be irritant Wear gloves, lab coat, and safety goggles Oxidising hydrogen peroxide is corrosive Wear gloves, lab coat, and safety goggles Fragile glassware eg measuring cylinder Place glassware in the middle of the table Variables: Independent variable: pH level Dependent variable: average volume of oxygen produced Control variable: Same size of potato, same amount of hydrogen peroxide. Destructive and non destructive testing of material: Destructive testing: hydrogen peroxide, pH, potato Non destructive testing: pH meter does not alter the solution, test tube, measuring cylinder
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