This investigation was on the effect temperature has on the rate that the enzyme trypsin hydrolyses its substrate, a protein found in milk (casein). This investigation was conducted under controlled conditions, the temperature being the changeable variable. Trypsin and its substrate (powdered milk which is a source of the protein casein) were heated in a water bath. The contents of the two tubes were then mixed together in order to find how long it takes for the milk solution to clear at different temperatures
Enzymes are designed to operate best at specific PH levels and also specific temperatures. They also work best at higher temperatures, so as temperature increases, so does the rate of chemical reaction. This is because heat energy and more kinetic energy results in more collisions between the enzyme molecules and the substrate molecules, therefore the substrate is more likely to enter the enzymes active site. For human enzymes the optimum temperature for enzymes to work is usually close to body temperature, therefore the enzyme trypsin is likely to have an optimum temperature of around 40ºC. Below this temperature, the enzyme and substrate have less kinetic energy, are moving more slowly and therefore are less likely to collide. Because of this, it was expected that the rate of reaction would be less at temperatures lower than body temperature. Also if the temperature gets too high and exceeds 40°C the rate of reaction should begin to decrease.
As shown on the graph, the speed of reaction drops eventually. This is because the enzyme is denatured and destroyed by the heat, this is because the active site has its specific shape due to the tertiary structure of the protein. Increasing the temperature will break bonds between the chains of amino acids. This disrupts the 3d structure of the protein, causing a permanent change
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