Effects of pH on Enzyme Activity

at that temperature, there was the most amount of catalase activity. On the pH graph, the

The temperature can have a major impact on an enzyme. According to Campbell Biology author Reece etc. 2011 “The enzyme reaction will increase as the temperature increase with the increasing temperature….substrates collide with active sites more frequently when the molecules move rapidly.”(Reece etc 2011) Every enzyme hits its optimal temperature the reaction will be at its highest point.(Reece etc. 2011) When the

Enzyme catalysis is dependant upon factors such as concentration of enzyme and substrate, temperature and pH. These factors determine the rate of reaction, and an increase in temperature or pH above the optimum will

Lab six requires students to observe the effects of pH and enzyme concentration on catecholase activity. Enzymes are organic catalysts that can affect the rate of a chemical reaction depending on the pH level and the concentration of the enzyme. As pH comes closer to a neutral pH the enzyme is at its greatest effectiveness. Also at the absorbance of a slope of 0.0122 the enzyme is affected greatly. The pH effect on enzymes can be tested by trying each pH level with a pH buffer of the same pH as labeled as the test tube and 1mL of potato juice, water, and catechol. This is all mixed together and put in the spectrophotometer to test how much is being absorbed at 420nm. As the effect on enzyme concentration can be tested almost the same way. This part of the exercise uses different amounts of pH 7-phosphate buffer and potato juice, and 1mL of catechol mixed together in a test tube. Each substance is put in the spectrophotometer at a wavelength set tot 420nm. The results are put down for every minute up to six minutes to see how enzyme concentration affects reaction rate. The results show that the pH 8 (0.494) affects the enzyme more than a pH of 4 (0.249), 6 (0.371), 7 (0.456), and 10 (0.126). Also the absorbance is greatest at a slope of 0.0122 with test tube C that has more effect on the reaction rate, than test tube A, B, and D.

The purpose of this experiment was to simply measure oxygen production rates released from decomposed hydrogen peroxide under different conditions (concentration of enzymes, temperature, and PH level).

Figure 2 is a representation of the average saturation of each cuvette at a specific point time as a function. The y-axis shows the specific saturation points from figure 1, and the x-axis provides the different levels of pH. The pH scale provided on the x-axis ranges from 0 to 14, 0 being the most acidic and 14 being the most basic. The point chosen from figure 1 was the saturation levels of each cuvette at 110 seconds. The saturation point was chosen because in the previous graph at time 110 seconds the reactions of

The time in the water bath was also controlled to ensure that the enzymes were left to react for the same amount of time, making the experiment

Slightly cooling or heating the test tube could also result in the proteins in the enzymes becoming denatured by the changes in the temperature. Enzymes also require very specific temperatures to function properly, so if the temperature changed too dramatically no reaction would occur. If the change in temperature was not dramatic, it could just affect the rate of reaction, so it might slow down the reaction, but the reaction would eventually occur.

The purpose of this investigation is to discover the effect of pH on the activity of catalase, an enzyme which plays the integral role of converting hydrogen peroxide into water and oxygen, and discover which pH level it will work at the most efficient rate (the optimum). The original hypothesis states that that the optimum would be at a pH is 7, due to the liver, where catalase usually resides, being neutral. The experiment consists of introducing the catalase to hydrogen peroxide, after exposure to certain solutions; hydrogen peroxide, water and hydrochloric acids, all containing the adjusted pH, and measuring the height of froth formed, an observable representation of the activity of the enzyme. The final data indicated that

As I forecasted the results proved correct that, the more concentrated the hydrogen peroxide is the higher the volume of the foam is and the less concentrated the hydrogen peroxide is the lower the volume of the foam will become. Other than the table of results the graph is also evidence to my true hypothesis. Each time the concentration of hydrogen peroxide doubles the level of foam increases but the more the concentration the foam reaches its constant point therefore slowly increasing. An example is when the 2% concentration of hydrogen peroxide was added the foam level was 13cm³ but when 4% was added to the next trial the level of foam greatly increased to 21 cm³ and as it reached its constant point, when 6% it slowed down and increased only 3 cm³ more which became 24 cm³.

must be above 8.5 and below 6.5. If the pH is too acidic, then the

Enzymes are high molecular weight molecules and are proteins in nature. Enzymes work as catalysts in biochemical reactions in living organisms. Enzyme Catecholase is found on in plants, animals as well as fungi and is responsible for the darkening of different fruits. In most cases enzymatic activities are influenced by a number of factors, among them is temperature, PH, enzyme concentration as well as substrate concentration (Silverthorn, 2004). In this experiment enzyme catecholase was used to investigate the effects of PH and enzyme concentration on it rate of reaction. A pH buffer was used to control the PH, potato juice was used as the substrate and water was used as a solvent.

In the following experiments we will measure precise amounts of potato extract as well as Phenylthiourea, combined with or without deionized water and in some instances change the temperature and observe and record the reaction. We will also investigate the different levels of prepared pH on varying samples of the potato extract and the Phenylthiourea and record the results. We will answer question such as what is the best temperature for optimum temperature reaction as well as the best pH level for the same reaction.

Hypothesis: If the pH is around seven, then the rate of the reaction for the enzyme peroxidase will be the highest. This is because the optimal pH range for the enzyme peroxidase is around seven and at its optimal pH an enzyme functions the best.

reaction rate increases. If the temperature of an enzyme gets to high the reaction rate will slow