Effects of Enzyme

In order to understand the activity of enzymes at different temperatures the ability of the enzyme to function can be measured. This is important in many applications such as Polymerase Chain Reaction for forensics as well as genetics research where manipulation of temperature-dependent enzymes allows for replication of DNA segments. Bennett states, “when the energy – measured as heat – increases in a chemical reaction the energy increases the reaction speed and reaction rate. (1969) This happens until a threshold though in many biological processes where positive energy input no longer increases reaction speed due to the inhibition of other factors – in this experiment that factor is the degradation or denaturing of the protein complex that is the enzyme working to catalyze the reaction. One would make the hypothesis that for any given enzyme there is a minimum reaction rate which increases with temperature then at a maximum point begins to be less and less efficient as the enzyme form no longer works to catalyze the reactions with its given substrates.

Materials and Methods After obtaining five clean test tubes and labeling them in order one through five, each were marked at one centimeter and at four centimeters from the bottom with a permanent marker. Next, the potato juice/catalase extract is added to each tube to the one centimeter mark. The following portion of the experiment was in segments for each tube. Tube one was placed in an ice-bath by adding ice and water in a 250ml beaker. Tube two was placed in the tube rack on the lab bench in a room temperature environment.

Tube three was placed in a water bath at 50 degrees celsius, and tube four was set in the 70 degree celsius water bath. Tube five was placed in a boiling water bath of a beaker on the hot plate while wearing goggles for protection. Each tube was then left in the conditional environment for ten minutes. The temperature of the boiling water, room temperature, and ice bath were measured by thermometer. After the ten minutes I used the thermometer to measure the temperatures of the room, ice, and boiling water. Then, after adding water, waited 30 seconds until the foaming in the tube, stopped.

The measured the amount of foam was recorded. Results After all the appropriate steps were taken, a table was created and I recorded each temperature that was in the tube and foam height as well. The temperate and the foam height were both recorded to see the resemblance and results concluding the temperature effect on enzymes. An example of my results are recreated as seen below (numbers and titles are accurate and the same as lab test) As shown in the table A, temperature and foam height is represented by different color lines on the graph. The purple line, represents temperature. The blue line represents foam height (mm).

As the temperature rose, the heigh of the foam decreased. This did not support my hypothesis. My hypothesis clearly stated,” If the temperature is really high, then the foam will rise highly. 50 degrees will be have the most amount of foam. ” This hypothesis was not supported because the highest amount of foam was found at 0 degrees. The enzymes reached optimum temperature, and then denaturing took place. In comparison to another lab, the same results occurred. Campbell Neil from students. cis stated, “The higher the concentration of substrate, the faster the reaction rate. ” This made my hypothesis invalid. Discussion

Although my hypothesis was not correct, the lab results agree with previous literature on the effects of temperature on enzyme activity. According to Susan Gilbert, “Enzymes are sensitive to their environmental conditions. Up to a point, the rate of the reaction will increase as a function of temperature because the substrates will collide more frequently with the enzyme active site. At extremes of pH or temperature, either high or low, the native structure of the enzyme will be compromised, and the molecule will become inactive”(2009). Enzymes are very sensitive and do the opposite of what most chemical reactions in this case.