An Investigation on the Rate of Reaction of the Enzyme Catalase on the Substrate Hydrogen Peroxide.

An enzyme is a protein macromolecule which acts as a catalyst, an agent which speeds up reactions without being consumed by it. They are vital to life; cellular chemical reactions would not occur fast enough to support life, without the aid of enzymes. They do this by lowering the activation energy (EA), which is the energy that must be added to the reactants at the start of reactions, it has to be reached in order for the reaction to occur (Reece, Wasserman and Urry). There are hundreds of enzymes known, but not all cells contain the same ones, an example of this is catalase which will be the experimental enzyme in the 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

How does changing the substrate concentration affect the rate of a catalase reaction in an enzyme? Hydrogen peroxide was used as the substrate and the rate was measured by oxygen production.

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 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 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

Substrate concentration also affects the rate of reaction as the greater the substrate concentration the faster the rate of reaction and all the active sites are filled. At this point the rate of reaction can only be increased if you add more enzymes in to make more active sites available.

The data from the experiment supports the hypothesis that catalase functions the most efficiently at a neutral pH of 7. Table 1 shows that catalase helped consume 3 mL of hydrogen peroxide in the solution with a pH of 7, more than any other solution. As the pH

We used apple, potato, and chicken liver to prove that not only beef liver contains catalase. The group conducted three experiments: one contained potato and H2O2, another had apple and H2O2, and the last had chicken liver and H2O2. We added 2mL of hydrogen peroxide (H2O2) to all three test tubes. The bubbling effect proved that all three had catalase in them. We realized that the more the substance bubbled the more catalase it contained, and that the less it bubbled, the less catalase there was. We also rated the reactions by the speed of the reaction in seconds, like we learned in part

Observing how the enzyme catalase found in chicken and beef livers breaks down hydrogen peroxide at varying pH levels and temperatures.

BACKGROUND: Catalase (the enzyme) is found in yeast, it breaks down hydrogen peroxide (the substrate) into water and oxygen according to this equation. 2H2O2(aq) -------------------> 2H2O(l) + O2(g) + catalase(aq) One molecule of catalase can break 40 million molecules of hydrogen peroxide each second. Factors that affect the rate of reaction § Increasing the temperature increases the kinetic energy at which the enzyme and substrate collide.

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.

Enzymes are biological catalyst, meaning that it increases the rate of reaction without contributing to the reaction or being used up. The amount in which the enzyme increases the rate of reaction is known as CATALYTIC ACTIVITY. An example of an enzyme is amylase, which convert starch into maltose (amylase is found in saliva). Furthermore, enzymes have specific jobs in which allow control different chemical reactions, hence why there are thousands of different enzymes in the human body.

As we study biomolecules, the subject of how do enzymes work comes up. The reasoning behind the catalase enzyme lab was to see how enzymes break down compounds. My objective being to see how the catalase enzyme will react to liver, potato and apple. We will also use a base or acid to see how these factors will affect the independent variable. My hypothesis is the liver and potato will react to the peroxide but the apple will not.

In the catalase activity there were three different procedures that led to the results that will be discussed. In the first procedure as you can see in table 1, a catalase was used to test what would occur to it when hydrogen peroxide is added. In this particular lab, potatoes were used as the catalase since they’re already buffered at pH 7.4, which will show better results than using any other catalase buffered at pH 7.0. The potato would speed up the breakdown of the hydrogen peroxide, this would result in the water and oxygen molecules being released (Mader, 2013). The cause of the oxygen molecules being released is that bubbling will begin to occur from the result of the hydrogen peroxide breaking apart (Mader, 2013). This explains why bubbles appear after a slice of potato was placed inside the test tube