Horseradish Peroxidase

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Effects of Temperature, PH, boiling and concentration on Horseradish Peroxidase

The purpose of this report is to find out the effect of change in the Temperature, PH, boiling, concentration in peroxidase activity. Peroxidase is an enzyme that converts toxic hydrogen peroxide (H2O2) into water and another harmless compound. In this experiment we use, turnips and horseradish roots which are rich in the peroxidase to study the activity of this enzyme. The activity of peroxidase with change in temperature was highest at 320 Celsius and lowest at 40C. The activity of peroxidase was highest at a pH of 7, while it was lowest at pH of 9.Peroxidase activity was very low and constant with boiled extract, while the activity was moderate and constant with normal extracts. Increase in the concentration of the enzyme, peroxidase increases rate of reaction i.e. peroxidase activity was highest with 2.0ml peroxidase extract, and lowest with 0.5ml peroxidase extract. In conclusion, increase in pH and boiling decrease peroxidase activity, while increase in temperature and concentration of enzyme, peroxidase increase peroxidase activity.

Enzymes are proteins that catalyze biological reactions. In biological entities, chemical reaction is involved in most of their metabolic processes. Chemical reactions have to overcome an activation energy for it to proceed. However, the higher the activation energy, the more energy is needed for that reaction to proceed. The body rather than produce that extra energy, opts to reduce the activation energy barrier the reactants have to overcome. One main reason they opt for this choice is that the extra energy needed for the reaction would be either too expensive for the body i.e. its ATP consumption or would be detrimental to the body if the energy is in form of heat. So enzymes are very important biological catalyst. Life would not exist for more complex multicellular organisms hadn’t it been for the role enzymes play in controlling metabolic processes. Enzymes are proteins whose function is dependent on its three dimensional structure. The function of an enzyme is in the structure of its active site which is a groove on the enzyme where the substrate would bind to. The shape of the active site has to be maintained in other for the enzyme to work in good fidelity. It is synonymous to a lock and key model where the lock is the active site and the key, the substrate. For a key to fit into a lock, the lock has to main internal structure. Different enzymes work in different manner in other to catalyze a substrate. Some enzymes need a cofactor that needs to be coupled with the substrate in other for it to bind to the active site of the enzyme. The binding between an enzyme and a substrate consist of a weak, non-covalent chemical bond which forms an enzyme-substrate complex. In this experiment, we are examining the factors that influence the rate of enzyme-catalyzed reaction. Factors such as pH, temperature, and boiling affect the rate of activity of an enzyme. The pH increases the +H ions or OH- ions present around the enzyme. Since enzymes are made of polar amino acids, they bind to the +H ions or OH- ions available rather than other amino acids, thereby altering the conformational structure of the protein (denaturation). Increase of temperature also denatures the enzymes. The high energy in heat breaks the weak hydrogen bonds, van dar waal interactions, and any other weak bond that holds the three dimensional structure of the protein. Like I mentioned above the function of an enzyme is in the structure of its active site. So therefore any process that influences that structure renders the enzyme nonfunctional. I hypothesize that enzyme activity would decrease with increase in temperature, pH, concentration, and boiling. The null hypothesis is that enzyme activity would not decrease with increase in temperature, pH, concentration, and boiling. Peroxidase is the enzyme we...
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