Inhibition of the decomposition of hydrogen peroxide by the catalase enzyme using copper sulphate.

Have a little read: ... Inhibition of the decomposition of hydrogen peroxide by the catalase enzyme using copper sulphate. Hydrogen peroxide is broken down by the enzyme catalase into water and oxygen. Enzymes are catalysts that speed up the rate of metabolic reactions. These reactions can take place without the catalyst but take a considerably longer amount of time. Enzymes can either break down larger molecules into smaller molecules or build smaller molecules into larger ones. In the case of hydrogen peroxide, larger molecules are broken down. All enzymes are globular proteins held together hydrogen bonds, ionic bonds and disulphide bridges in a distinct three-dimensional shape and its shape is specific to each enzyme, as one substrate will fit only one active site. This is illustrated in the 'Lock and Key Hypothesis.' The lock and key hypothesis was to explain why enzymes are specific and will only work on particular substrates. The hypothesis tells us that the substrate fits the active site exactly and because every substrate is different each enzyme has an active site the correct shape for only one substrate and they have to fit each other exactly. As the products have a different shape to the substrate they no longer fit the active site and are repelled by the enzyme. The other theory is the 'Induced Fit Theory.' This suggests that the acive site is not exactly the same shape as the substrate, but slightly larger and therefore allows the active site to mould itself around the substrate. The active site can only catalyse the reaction when tightly bonded. After the reaction has occurred, the product is repelled by the active site and the enzyme returns to its relaxed state. Temperature can alter the active site at high temperatures as it changes the shape of the enzyme and destroys the active site. This means the substrate can no longer be catalysed and therefore the rate of reaction decreases. Up until the temperature denatures the enzyme, every 10sc increase in temperature doubles the rate of reaction. Cooling the enzyme will inactivate the enzyme, but doesn't denature it and therefore is able to work again when it is heated up. PH also affects the rate of reaction. Small changes in pH can change the rate of reaction without denaturing the enzyme, but at the extremes of pH the enzyme can become unstable and denatured. Free hydrogen or Hydroxyl ions can affect the charges on the