Practical investigation in the chemistry lab of Llandrillo College in Wales (Lorenzo S. 3D).

Enzymes are protein molecules which are used to speed up specific reactions in living cells. Each enzyme just performs one particular reaction, for example catalase removes the poisonous hydrogen peroxide from the cells as shown in the equation: 2 H2O2(aq) ® 2 H2O(aq) + O2(g). Catalase is found in liver and in vegetables, such as potato and germinating mung beans. Materials and Methods: 1) in a mortar grind with a pestle 2 germinating mung beans, adding 5 ml of distilled water to produce a smooth paste containing the catalase enzyme; 2) using forceps, dip a filter paper disc into the enzyme solution and wipe off the excess on a paper towel; 3) drop the filter paper disc into the hydrogen peroxide solutions (five different concentrations: 2%; 4%; 6%; 8%; 10% v/v); 4) time how long the disc takes to float up to the surface; 5) remove the disc from the test tube using forceps and discard. Repeat 3 times for each dilution. 6) complete a table of your results (average ± standard error) and draw a graph.

plancton laboratorio

Results and Discussion: the oxygen, released during the reaction above, pushes the filter paper disc up to the surface. The time occured to float up decrease as well as the hydrogen peroxide concentration increase. The enzymes are inactivated by heating and so the reaction doesn’t happen, if you boiled the mung beans first.


Informazioni su elenacosi

Insegnante di Scienze Naturali (Biologia, Chimica, Geologia, Astronomia) presso la scuola secondaria superiore
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