Enzyme Concentration Lab

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

The topic of this lab is on biochemistry.This experiment was conducted to show how cells prevent the build of hydrogen peroxide in tissues. My group consisted of Lekha, Ruth, and Jason. There were used two different concentrations of hydrogen peroxide through this experiment , 1.5% and 3%. By testing two different types it is easier to understand how the H2O2 and catalase react with one another. To do this both the yeast, which was our catalase, and H2O2 were mixed together in a beaker. Each concentration was tested out twice for more accurate results . 1.5% concentrated H2O2 had an average reaction rate of 10.5 seconds while 3% concentrated H2O2 had an average reaction rate of 7.5 seconds. From this experiment we learned that by increasing the concentration of H2O2 and chemically combining it with a catalase it will speed up the reaction. Enzymes speed up chemical reactions . The independent variable in this experiment was the concentration of the H2O2. Some key vocabulary words are Catalase, enzyme, hydrogen peroxide ( H2O2), and concentration.

From Figure 4, the maximum velocity is the highest point on the curve and the constant (km) is ½ the maximum velocity. However, it is difficult to estimate Vmax using Michaelis-Menten curve with precision since the limits of the hyperbolic curve deviate at varying concentrations of the substrate. The data can be linearized using Lineweaver-Burk Plot to obtain Vmax and Km as follows: Slope=Km/V_max

This investigation will be carried out to investigate the rate of reaction of the enzyme catalase on the substrate hydrogen peroxide.

Hypothesis: If the concentration of an substrate is increased then the time it takes for the yeast spheres to rise will decrease because there is more substrate for the enzyme to break down, creating more oxygen, faster.

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.

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.

2) Yes, the rate of gas production increased as more yeast was added, since more enzyme was able to convert hydrogen peroxide more quickly.

We hypothesized that a medium pH buffer added to the hydrogen peroxide an peroxidase reaction would be the best condition for the enzyme activity due to it being the more neutral than the high, being basic, and low, being acidic, pH.

We did this to test which test tube would contain the highest concentration of glucose. What we wanted to know was if the lactase would affect the function of the enzyme. Our hypothesis is the lactase functions within a narrow pH and that will change in pH would affect the function of the enzyme. We predict that if we change the environmental factors it will have an effect the function of the enzyme if the pH is outside the range in its optimum activity. Our hypothesis was then proven because the reaction only occurred in a neutral and acidic state of pH, not basic. Which means the enzymes prime ability to function is a neutral, and acidic pH range.

To begin the experiment, six 16 x 150 mm test tubes were chosen, three marked “enzyme” and three marked “substrate.” For the baseline test using a 10 mL syringe and two 5 mL syringes, 7 mL of distilled water, 0.2 mL of a 0.3% guaiacol solution, and 0.3 mL of 0.1% hydrogen peroxide were added to the first substrate tube, containing a total volume of 7.5 mL. The baseline substrate test tube was then covered with a piece of Parafilm and gently mixed. To the baseline enzyme test tube, 1.5 mL of the standard 25g/400 mL concentration of peroxidase and 6.0 mL of distilled water were added; a piece of Parafilm also covered the tube then the test tube was gently mixed. The other two substrate tubes, one for the low concentration test and one for the

Higher levels of solution should produce higher levels of product. The independent variable for the control group data and the experiment data is the yeast concentration. The dependent variable for the control group data and the experiment data is how much oxygen is produced. The Constant for the control group data and the experiment data is time and amount of hydrogen peroxide. The products of the experiment will increase if the levels of reactants increase. Denatured yeast may cause change in the reaction of the experiment. For all trials of the control group, the concentration of yeast is 6ml. For the experiment data, the yeast concentration varies from 8mL, 10 mL, 12 mL, 14 mL, and 16 mL. The temperature may cause change in the reaction of the combination of yeast and hydrogen peroxide

The materials needed for the experiment is a vial of the blood serum containing the enzyme alkaline phosphatase, a stock solution of 10mM of p-nitrophenyl phosphate in water (substrate). 5mM of phenyl phosphate in pH10 buffer solution, 0.1NaOH solution to stop enzyme activity, buffer solution at pH10 and a vortex mixer to mix the solution.

The reaction slows down when yeast is added because the yeast inhibits the magnesium and acetic acid from reacting. In the lab, the first two trials did not use yeast and had rates of 0.682 bubbles per second and 0.703 bubbles per second respectively. After adding 0.0141 grams of yeast to the reaction, the rate lowered significantly to 0.285. Adding even more yeast amounting to 0.0939 grams slowed the rate down even more to 0.26 bubbles per second. It is clear that the more yeast that is added, the more the reaction slows down because the yeast prevents the reactants from undergoing the reaction. The reaction was faster without the yeast because their was no foreign substance blocking the reaction. The yeast slowed down the reaction by attaching

The data reveals how as the concentration increases, so does the amount of oxygen produced per second. Based on the experiment conducted, at concentration of 4%, 0.62 cm3 of oxygen was being produced per second; at 8%, 1.6 cm3 was being produced per second; at 12%, 2.15 cm3 was being produced per second; at 16%, 3.02 cm3 was being produced per second; at 20%, 3.31 cm3 was being produced per second. The research question has not been fully fulfilled because although it proved how the substrate hydrogen peroxide (substrate) affects the rate of reaction of the enzyme catalase, there were still inaccuracies when conducting the experiment and the graph did not reach the maximum possible rate of reaction. The hypothesis mentioned is still accepted considering that the graph and the chart managed to successfully show how as the substrate concentration increases, the reaction will go up at a directly proportional rate until the solution becomes saturated with the hydrogen peroxide