Factors That Influence Catalase Activity

This experiment looked at how substrate concentration can affect enzyme activity. In this case the substrate was hydrogen peroxide and the enzyme was catalase. Pieces of meat providing the catalase were added to increasing concentrations of hydrogen peroxide in order to measure the effect of hydrogen peroxide concentrations on the enzyme’s activity. The variable measured was oxygen produced, as water would be too difficult to measure with basic equipment.

Hypothesis: If the concentration of the substrate is increased, then the rate of enzyme activity will decrease. This is because as the concentration of the substrate increases, there is an increasing amount of occupied active sites at any given moment. This will cause a decrease in the rate of enzyme activity as substrate-active site collisions are increasingly slowed down thus bringing down the rate of enzyme activity.

As seen on table 1, the hypothesis in the introduction of this lab has been supported by the procedures. As the temperature varied from catalases optimal of 37° C, the reaction rate of catalase decreased. 37°C had the highest reaction rate of the three, at 3, while 4°C had the middle rate of reaction at 2.5, and 100° C had the lowest reaction rate of 0.5.

The reaction taking place is hydrogen peroxide (H2O2) being broken down into oxygen gas(O2), and water (H2O). The function of the enzyme catalase is to help with the speed of the chemical reaction being done. The enzyme mixes with oxygen to quicken the reaction. We added the chemical Hydrochloric Acid (HCI) to the enzyme mixture to see how it would affect the rate of the reaction. The two things affect enzyme function is temperature and pH. We decided to use Hydrochloric Acid, it has a low pH making it an acidic chemical. We wanted to see if a chemical with an acid pH would affect the speed of the enzyme function. If the rate of the breakdown of hydrogen peroxide is affected by pH, then the enzyme will speed up the reaction time. Turn on the hot plate to heat up the mixture of Catalase (Activated Yeast). Once it hits between 30-37ºC the yeast is ready to use.

As illustrated in Table 1, increase in temperature resulted in the increase of the rate of catalase activity to a certain range. After the range, the temperature would continue to increase, but the rate of catalase activity will decrease significantly. Rate of enzyme activity increased as temperature increased is supported by the Collision Theory. The collision theory states in order for a reaction to occur, reacting particles must collide with one another (McGraw-Hill Ryerson Chemistry 12). Particles must collide with sufficient energy to overcome activation energy and with the correct geometrical orientation. Increase in temperature and rate of catalase activity, increases kinetic energy of hydrogen peroxide molecules. This allows a faster movement of hydrogen peroxide molecules increasing the collision frequency and the effectiveness of the collisions. As a result, more reactions will be speed up and increase catalase activity. The range where the rate of catalase activity is the highest is at 60°C. This would be the peak for the catalase. At 60°C, the most collisions, more effective collisions take place and hydrogen bonds are loose making it easier for catalase to act on hydrogen peroxide. As a result of this 60°C is the temperature peak for the catalase. After 60°C, the rate of catalase activity increases. This is because enzymes are very fragile macromolecules. After a certain temperature range, intramolecular bonds are broken due to amino acids vibrations. This leads to the enzyme denaturing. Denaturing is when the structures in the enzyme has been altered and cannot be

The purpose of this experiment was to analyze the effects of substrate concentration and temperature on activity of catalase. The activity was measured by observing the amount of time it took for 10 mL of oxygen to evolve as an outcome of the catalyzed breakdown of hydrogen peroxide. Increased temperature and substrate concentration will both effect the activity of a catalase enzyme. We used 4 different temperatures of an enzyme, as well as a variety of scientific materials. The results of this experiment confirmed the hypothesis that was tested.

Between 60ºC and 80ºC the rate of enzyme decreased slowly until no enzyme are found at 80ºC. (Decreased because the line is going down. Slowly because the slope of the line between the two points is not as steep as it was previously and the line is flattening slowly). 4. This graph 3.1 shown most the enzyme reaction optimum temperature at 40ºC. But at higher temperature enzymes are denatured.

During the lab various factors were changed in order to compare how different environmental changes affected the rate of the reaction. A first test was conducted with liver and hydrogen peroxide without an induced temperature change scored a 5. Next, the catalase (liver) was heated to a high temperature and then hydrogen peroxide was added. The reaction was not as fast, and produced a score of 3. A similar test was done using another piece of liver but was placed in an ice bath and then hydrogen peroxide was added. This produced an even slower reaction rate of 2. These three tests demonstrate how temperature greatly influences the rate of enzyme action. When enzymes reach above boiling point, they are denatured and no longer function. Optimal temperatures for enzymes to function is 35-40 degrees Celsius. When the temperature is lower than optimal, slow reactions occur. Further experiments were conducted to show how pH levels affected enzyme action. Two mL of hydrogen peroxide was added to three test tubes. Then, HCl was added to test tube 1, NaOH was

If the concentration of the catalase is decreased, then enzyme activity will decrease as well, because there is less catalase, which is what sparks the chemical reaction.

Enzymes are a type of protein that assist in chemical reactions and speed them up. Catalase is an enzyme that breaks down hydrogen peroxide (H2O2) in water and oxygen. Enzymes can denature if their pH or temperature change to an intolerable level. This is when the enzyme’s shape changes so the subtrate can not fit into it. Subtrates need to fit into the enzyme for the enzymes to be useful in reactions, or else they are useless. The goal of this study was to observe how the enzyme activity would be affected if we changed the temperature or pH levels. Because the reaction of catalase and hydrogen peroxide produces oxygen, the way to observe this experiment would be to look at the amount of foam made.

Introduction: Enzymes are defined as being molecules that function as biological catalysts, increasing the rate of reaction without being consumed by the reaction. They allow molecules to use less energy to create the reaction. Each enzyme has a specific shape for its substrate and only that substrate can bind to the enzyme to create the reaction. If environmental factors change such as PH levels or temperature this could cause enzymes to change their shape and therefore their function. If the enzyme structure changes the molecules can’t bind to them causing the reactions to not be able to be made. The enzyme for this experiment was the catalase enzyme which is used for the degradation of hydrogen peroxide, it is a protective enzyme located in nearly all animal cells. After researching the topic finding the ways enzymes are effected by certain environmental factors drove to do the experiment. My hypothesis for this reaction was if the temperature goes up the enzyme reaction will go down because of denaturation. According to my hypothesis at 0 degrees Celsius the enzyme reaction should be the highest and at 23 degrees it should go down at 37 it should keep going down and at 55 degrees the enzyme reaction rate should be the lowest. This experiment is so important because the catalase enzyme breaks down H2O2 which is poisonous to our bodies and turns it into two chemicals that are not harmful to us,

A catalase is an enzyme that protects cells from oxidative damage. It does so by breaking down hydrogen peroxide, which the catalase generates during cell metabolism. Catalase deactivates millions of hydrogen peroxide molecules per second. First, the catalase breaks down hydrogen peroxide by removing and binding one oxygen atom and next releasing the rest of the hydrogen peroxide molecule as water. Then, the catalase breaks down a second hydrogen peroxide molecule by releasing oxygen gas and water. The optimum temperature- the temperature at which the enzyme is the most active at- is 40°C. Also, the optimum pH level for the catalase is pH 7.

In the catalase experiment, the enzyme will act as a catalase that speed up the chemical reaction, in this case the yeast; moreover, the substrate is the hydrogen peroxide. The product of the enzyme-substrate complex is H2O and O2. The rate of oxygen that is being produced is caused by either increasing the amount of product or decreasing the amount of reactants. Factors that affect the results are the temperature, which will change the environment of the enzyme to cause the enzyme to either denature or increase the reaction rate.

The result of our data isn’t accurate, and has flaws in terms of timing and accuracy. Next time, before I time the enzyme catalase for 2 minutes when I insert and get the enzyme catalase out, I will time 15 seconds, instead timing at random and inconsistently. Also, our experiment only used 4 different temperatures of the hydroperoxide, which consists the idea that next time we can increase the sample sizes by using more temperatures. Next time, we should find out the temperature when the enzyme catalase lose its its shape. Since the enzyme lost its shape until warm water that was 43° and lost its shape at hot water of 95.8° we can have more temperature between both the warm and the hot water.

The question being answered by these experiments is: How do different conditions affect the productivity of enzymes? Enzymes are produced by cells and they act as catalysts, which means they are organic molecules that speed up chemical reactions. How effectively they work depends on the conditions they are in, such as level of temperature, pH level, substrate concentration, and salt concentration. In these experiments, Catalase will be placed in different conditions with hydrogen peroxide. How active the enzyme is in these different conditions will be measured by the amount of oxygen gas being produced. A very high increase in oxygen will indicate a high reaction rate and a low production of oxygen will show that there is a low reaction rate. On the other hand, if there is no change in the level of oxygen, it will indicate that the Catalase is denatured and is no longer functioning.