Lab 9 Handout and Post Lab Questions Essay

The hypothesis is that catalase activity will increase exponentially with higher concentrations of hydrogen peroxide until all catalase active sites are filled, in which case the

In the experiment we used Turnip, Hydrogen Peroxide, Distilled Water, and Guaiacol as my substances. On the first activity, Effect of Enzyme concentration of Reaction Rate for low enzyme concentration, we tested three concentrations of the turnip extract, and hydrogen peroxide. For the Turnip Extract I used 0.5 ml, 1.0 ml, and 2.0 ml. For hydrogen peroxide we used 0.1 ml, 0.2 ml, and 0.4 ml. We used a control to see the standard, and used a control for each enzyme concentration used. The control contains turnip extract and the color reagent, Guaiacol. We prepared my substrate tubes separately from the enzyme tubes. My substrate tube

gas bubbles serves as evidence that the catalase enzyme is working. As catalase is breaking the

I did see occasional bubbles, which could be due to the slight chemical reaction of the two chemicals. However, it was obviously not as strong as with the salt since the salt changed

Students will be observing normal catalase reaction, the effect of temperature on enzyme activity, and the effect of pH on enzyme activity in this experiment. The enzymes will all around perform better when exposed in room temperature than when it is exposed to hot and cold temperatures. This is based on the fact that the higher the temperature, the better the enzymes will perform, but as the temperature reaches a certain high degree, the enzymes will start to denature, or lose their function.

If different amounts of enzyme solution are added to the hydrogen peroxide, then the highest amount of enzymes will have the greatest reaction rate because enzymes catalyze reactions, meaning more oxygen will be produced quicker.

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.

For my negative controls I would run the reaction in several separate ways. First, omit the substrate (to make sure the enzyme is only acting on hydrogen peroxide and not something else in the mixture). Second, omit the enzyme (to make sure it's not self-catalyzed breakdown). Third, I would incubate substrate with an unrelated protein like albumin (to make sure it's not just the presence of protein that mediates the breakdown of hydrogen peroxide).

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

The purpose of this experiment was to record catalase enzyme activity with different temperatures and substrate concentrations. It was hypothesized that, until all active sites were bound, as the substrate concentration increased, the reaction rate would increase. The first experiment consisted of five different substrate concentrations, 0.8%, 0.4%, 0.2%, 0.1%, and 0% H2O2. The second experiment was completed using 0.8% substrate concentration and four different temperatures of enzymes ranging from cold to boiled. It was hypothesized that as the temperature increased, the reaction rate would increase. This would occur until the enzyme was denatured. The results from the two experiments show that the more substrate concentration,

The independent variable in this investigation is pH. Each individual enzyme has it’s own pH characteristic. This is because the hydrogen and ionic bonds between –NH2 and –COOH groups of the polypeptides that make up the enzyme, fix the exact arrangement of the active site of an enzyme. It is crucial to be aware of how even small changes in the

6. Plan and conduct your own investigation into one other factor that affects the activity of catalase, you may use this as the basis for your investigation but if it is to be for moderation of internal assessment you must modify it substantially.

After measuring equal amounts of distilled water and either adding or subtracting catechol which we referred to as the substrate some reactions was seen immediately. After which we were able to get data that supported my original hypothesis that in the addition of substrate and an enzyme the reaction would be present in varying degrees dependent on whether a temperature change was provided or not. In the second part of the experiment we were testing the inhibition action of Catechol Oxidase at different levels in several tubes of varying samples of potato extract, phenylthiourea (PTU) and distilled water. The experiment showed that (PTU) bonded with the extract and the water causing a reaction whereas there was no reaction in tube # 1 where there was an equal amount of everything in the tube. And test tube # 3 was the control tube where the (PTU) was eliminated as to observe if there was any reaction at all. Of course with the whole experiment we had to be very careful as to add the catechol last to ensure no premature reaction. It was hypothesized that (PTU) is a non -competitive inhibitor and doubling the substrate will have no reversal effect.

This experiment is designed to analyze how the enzyme catalase activity is affected by the pH levels. The experiment has also been designed to outline all of the directions and the ways by which the observation can be made clearly and accurately. Yeast, will be used as the enzyme and hydrogen peroxide will be used as a substrate. This experiment will be used to determine the effects of the concentration of the hydrogen peroxide versus the rate of reaction of the enzyme catalase.

To find the effect of temperature on the activity of an enzyme, the experiment deals with the steps as follows. First, 3 mL if pH 7 phosphate buffer was used to fill three different test tubes that were labeled 10, 24, and 50. These three test tubes were set in three different temperature settings. The first test tube was placed in an ice-water bath for ten minutes until it reached a temperature of 2° C or less. The second tube’s temperature setting was at room temperature until a temperature of 21°C was reached. The third tube was placed in a beaker of warm-water until the contents of the beaker reached a temperature setting of 60° C. There were four more test tubes that were included in the procedure. Two of the test tubes contained potato juice were one was put in ice and the other was placed in warm-water. The other two test tubes contained catechol. One test tube was put in ice and the other in warm water. After