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Enzyme activity using the enzyme catalase in different plant sources

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LE BOCAGE INTERNATIONAL SCHOOL Enzyme activity using the enzyme catalase in different plant sources Practical 11 Mahmood Zabioullah Fokeerbux 9/10/2009 Title: Enzyme activity using the catalase enzyme in different plant sources Background information: Enzymes are biological catalysts. They are made of protein. They speed up the rate of reaction in the body and without taking part in the reaction. The surface of the enzyme where the substrate binds to is called the active site, which has a specific conformation. Normally the active site is enzyme-substrate specific. This is explained by the lock and key theory, where the enzyme is the lock and the substrate is the key. Enzyme activity, specifically is the rate at which the enzyme catalyses the chemical reaction. This is affected by three main factors: 1) temperature, 2) pH and 3) substrate concentration. Another factor is the enzyme concentration but it is not included in the syllabus. Hydrogen peroxide is a weak acidic but has very strong oxidizing properties. It is a by-product of respiration thus very harmful to cells. Hydrogen peroxide is catalysed by the enzyme catalase to form water and oxygen in the body as soon as possible: 2H2O2 (l) ...read more.


goggles * Handle hydrogen peroxide with care, it is harmful, corrosive and an oxidant * Wear lab coat if provided * Keep your station clean * After using the apparatus, put them in the basin to be washed. * Try not to be too close to another person's work station * Put all stools under the table * Make sure there are no parallax error when reading volumes etc * Take precaution when cutting the food samples as the cutter used is very sharp * If help is needed, call the supervisor/teacher but do not try experimenting without knowing what is going on. Data Collection Food sample Height of foam produced/ mm 1st 2nd 3rd 4th 5th Apple 0.5 0.1 0.1 1.0 1.0 Onion 0.5 0.5 0.5 2.0 0.5 Beetroot 2.0 2.0 0.1 2.0 2.0 Carrot 5.0 2.0 4.0 0.1 1.0 Potato 6.0 4.0 6.0 5.0 5.0 Data processing Food sample Mean Standard deviation Range/mm Apple 0.54 0.45 0.9 Onion 0.8 0.67 1.5 Beetroot 1.62 0.85 1.9 Carrot 2.42 2.04 4.9 potato 5.2 0.84 2.0 (Table 1: error bars showing 5% error from values) Conclusion and evaluation Equipment used and manipulating errors How can it be modified/improved The food samples were cut into cylinders; therefore, the surface area to rate of reaction was not constant. ...read more.


According to the figures and the graph above, it was clearly seen that potato had the highest enzyme activity than the other food samples. Therefore, it can be said that potato contains most catalase, followed by carrot, then beetroot, onion and finally apple. According to research, it was found that 37oC is the optimum temperature for the enzyme catalase in potato, therefore, it can be said that the enzyme worked at its best. According to a research the optimum activity of catalase in apple is 50oC, probably that is why the obtain result is so low but according to another research, it was found that apple is catalase activity absent like other fruits, due to their high acidity. The standard deviation for all the food samples except carrot lies within �1 S.D. This shows that the recorded values in the carrot experiment are not clustered to the mean and there are outliers in the recorded values. The highest range in height of foam is from the food sample (carrot), probably, in one of the experiment, the foil was moved, a little air space was created and the oxygen managed to escape. Sources: http://www.labtestsonline.org/understanding/analytes/blood_gases/sample.html date accessed: (01/09/09) http://www.123helpme.com/view.asp?id=120339 date accessed: (01/09/09) http://www.neiljohan.com/projects/biology/enzymes.htm date accessed: (01/09/09) The Catalase Experiment." 123HelpMe.com. 20 Aug 2009 http://www.123HelpMe.com/view.asp?id=120443 date accessed: (01/09/09) http://www.pjbs.org/pjnonline/fin244.pdf date accessed: (12/09/09) ?? ?? ?? ?? ...read more.

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