Effect Of Ph On The Activity Of Catalase

“Peroxisomes are so named because they usually contain enzymes that use oxygen to remove hydrogen atoms from specific substrates in an oxidative reaction that produces hydrogen peroxide (H2O2) (McCance & Huether, pg. 7).

Peroxidase is an enzyme found in potatoes that catalyzes the breakdown of hydrogen peroxide, H2O2, into O2 gas and water. We examined the different pH environments that can affect the enzyme activity during the breakdown of H2O2. In order to do this, we added different levels of pH, low, medium, and high, into different test tubes with the enzyme and H2O2, and we then inverted the tube. The amount of O2 gas produced was then measured and recorded. The result was that the higher pH produced more gas, followed by medium pH, then low pH. The enzymes were more active in the pH of about 10. It increased

Catechol, in the presence of oxygen is oxidized by catechol oxidase to form benzoquinone (Harel et al., 1964). Bananas and potatoes contain catechol oxidase that acts on catechol which is initially colorless and converts it to brown (Harel et al., 1964). In this experiment, the effect of pH on the activity of catechol oxidase was conducted using buffers ranging from pH2 to pH10. Two trials were conducted due to the first trial results being altered by an external factor. The results were acquired by taking readings every 2 minutes for 20 minutes from a spectrophotometer and then recorded on to the table. The data collected in the table were then made into graphs to illustrate the influence of pH on the catechol oxidase catalyzed reaction. After analysis, the data revealed that pH did have a significant influence on the enzyme as recorded by absorbance per minute. However, the data was collected was not accurate due to external factors, thus the results are debatable and should be experimented again for validation.

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.

Its role as an enzyme is to quickly break down hydrogen peroxide (H2O2) into water and oxygen, preventing cellular damages. H2O2 is produced as a harmful by-product in all organisms that use molecular oxygen, so catalase is especially abundant in liver cells of humans and other organisms, because the liver is an organ that detoxifies many harmful substances including peroxides (Lab Manual). The catalase and hydrogen peroxide reaction process is as seen as below:

4.a) Describe the effect of low (pH 2) and high (pH 12) pH levels on catalase activity.

In this lab we attempted to find a relationship between pH and the productivity of the enzyme catalase. We used the method of testing called the ‘submarine’ method, and tested the velocity of the reaction in bubbles per 30 seconds. We measured this data by inserting 1 mL of H2O2, 1 mL of a vinegar and water solution that varies in pH, and 1 mL of H2O with 20 µL of liver puree into a narrow-mouthed piped base, dropped that into a flat bottomed test tube filled with 30 mL of distilled room temperature water, and then counted the number of bubbles that were produced. We found an exponential relationship between pH and enzyme velocity, as the pH increased the velocity first remained close to constant before dramatically increasing. This can be

The reactions within cells are catalyzed by a specific type of proteins known as enzymes. Enzymes catalyze the rate of a specific reaction by recuing the amount of energy needed to get the chemical reaction started or the activation of energy. The activity of these enzymes is dependent upon several different things including the shape of the molecule, and specifically the concentration of the enzyme and substrate (hydrogen peroxide). This laboratory exercise will be conducted under a controlled environment to determine the influence of pH on the enzyme catalase.

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.

An Investigation on the rate of reaction of the enzyme Catalase on the substrate Hydrogen peroxide.

Wear safety goggles to protect the eyes from any splashes and wearing gloves is recommended when handling acids and

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 chemical hydrogen peroxide(H₂O₂) is broken down by the enzyme catalase. Hydrogen peroxide is a byproduct formed in cellular reactions that, if not broken down, could inflict severe damage to the cell. Catalase is an enzyme that breaks down hydrogen peroxide in to water and oxygen. How efficient and strong the enzymes reaction to break down H₂O₂ determines largely on temperature and pH level. An enzyme only functions within a set pH and temperature range. Beyond that it becomes denatured, rendering it useless. The purpose of this lab is to determine at which temperature and pH level the enzyme catalase reacts best. Catalase in chicken and beef livers will be used to do the lab because enzymes still function after death as long as they are kept refrigerated at a low temperature.

Hydrogen peroxide is a toxic byproduct of cellular functions. To maintain hydrogen peroxide levels the catalase enzyme deconstructs hydrogen peroxide and reconstructs the reactants into oxygen gas and water. The catalase enzyme is found inside cells of most plants and animals. Regulating the levels of hydrogen peroxide is crucial in homeostasis and analyzing it’s optimal conditions for performance is just as important. To understand the optimal environment for this enzyme, they are put into different environments based off protein activity (enzymes are proteins). Catalase samples will be put into different hydrogen peroxide environments based off pH and temperature. The more active the enzyme, the more oxygen and water it will produce. Enzyme activity can be seen through the release of oxygen in the hydrogen peroxide. Since oxygen cannot be accurately measured, the data will consist of the longevity of the reaction in different environments. If the pH is higher than 7, then the reaction rate will increase due to the ample amount of hydrogen ions in the hydrogen peroxide. However the pH level cannot be higher than 10 or else there will be too many hydrogen atoms in the peroxide for the enzyme to be able to deconstruct them. If the temperature is increased, then the reaction rate will increase due to the ample amount of energy and movement in the hydrogen peroxide and enzyme.

The aim of my investigation is to see how pH affects the activity of potato tissue catalase, during the decomposition of hydrogen peroxide to produce water and oxygen.