Enzyme Catalase Background

Catalase is an important enzyme that protects cells from oxidative damage, which hydrogen peroxide can cause. It is an incredibly efficient enzyme where one catalase molecule can convert millions of hydrogen peroxide molecules each second.

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.

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

If another enzyme like lactase is used, no reaction would take place because the substrate, hydrogen peroxide, wouldn’t fit into the active site.

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,

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 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.

With all living organisms, a process known as cell respiration is integral in order to provide the body with an essential form of energy, adenosine triphosphate (ATP). Oxygen, although an essential part of this process, can form reactants from colliding with electrons associated with carrier molecules. (pb101.rcsb.org, 2017). Hydrogen peroxide is an integral product of this reaction but is known to impose negative effects on the body if high levels are introduced. Explicitly, this reaction is caused “If oxygen runs into (one of these) carrier molecules, the electron may be accidentally transferred to it. This converts oxygen into dangerous compounds such as superoxide radicals and hydrogen peroxide, which can attack the delicate sulphur atoms and metal ions in proteins.” (pdbh101.rcb.org, 2017). Research has suggested that the hydrogen peroxide can be converted into hydroxyl radicals, known to mutate DNA, which can potentially cause bodily harm due to DNA’s role in the synthesis of proteins. These radicals can cause detrimental effects on the human body, and studies have suggested a link to ageing. Due to the harmful effects of these H2o2, it is important that the body finds a way to dispose of hydrogen peroxide before concentrations are too great.

Its function is the speed up the decomposition of Hydrogen peroxide within cells. This is an important function within living animals because it becomes a poisonous substance. Catalase breaks apart hydrogen peroxide into water and oxygen through enzyme-substrate complexes. (Tully) The shape of catalase is complex with various alpha-helices and beta-sheets.

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

The catalase enzyme is so critical to our health that it is found in nearly every living organism on the planet that is exposed to oxygen. This antioxidant enzyme can catalyze the conversion of hydrogen peroxide into water and oxygen. Hydrogen peroxide is a by-product of cell metabolism, which serves some useful functions including healthy immune response. (Group, 2013) Catalase has one of the highest rates of turnover when compared to all other enzymes. In other words, one catalase enzyme can change 40 million molecules of hydrogen peroxide into water and oxygen in just one second. In fact, catalase enzymes act to protect our cells, counteracting and balancing the continual production of hydrogen peroxide. Because of its undeniable, scientifically-proven

Catalase attempts to accelerate the deterioration of hydrogen peroxide into oxygen

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.

generally act as a catalase that initially bring about a chemical reaction.” Enzymes play an

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.