Essay On Catalase Activity

ABSTRACT
Catalase is an enzyme found in both plant and animal tissue. It catalyses the breakdown of hydrogen peroxide into water and oxygen.
The main aim of the investigation was to find out if temperature has a long term effect on the rate of catalase activity in plant tissue.
Plant tissue was left at room temperature, boiled or frozen and then grinded to a paste. It was then centrifuged and supernatant was tested with hydrogen peroxide solution. The calculation r=1/t was used to determine the rate. The results of the three experiments suggest that low temperatures do not have a long term effect on catalase activity while high temperatures do. When frozen, the tissue gives results similar to that given when tissue is kept at room temperature.

Catalase is an enzyme found in all aerobic cells. It is a composed of four polypeptide chains, each 500+ amino acids long. Catalase was first discovered in 1818 when Louis Jacques Thénard, who also discovered hydrogen peroxide, noticed its breakdown was caused by an unknown substance. Oscar Loew gave it the name catalase in 1900, and found it in many living organisms. In 1981, the three-dimensional structure of catalase was

It was found in many previous studies that high temperature greatly reduces the activity of catalase in plant tissue (Eyster, H. Clyde, 1950). In this experiment, the tissue was boiled at 100°C, almost double the critical temperature which has been found to be 55°C.
There was much opportunity for human error in this experiment, for example it was hard to stop the timer at exact moment that the disk floated to surface of hydrogen peroxide solution, so time taken may not show true representation of how long the disk actually took to reach surface and so results from rate calculations may be slightly inaccurate and not entirely reliable.
The three repeats of each experiment was found to be inadequate as it did not give a large enough range of results, in future experiments a larger variety of tissues should be used, a wider range of temperatures, aand at least five repeats should be carried out in order to obtain wider, more interesting and reliable results on catalase activity in plant tissue. The use of tissue kept at room temperature for the entire experiment was successful as it provided a clear comparison with the tissue that had been boiled or frozen. During the investigation, the same pieces of equipment ie the centrifuge and scale were used for every measurement to ensure that there was no variation in results due to technical