The Effect Of Temperature On The Enzyme Peroxidase

For enzymes to be useful in a reaction, the substrate needs to bind with the enzymes active site. The active site is specific for a

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.

· I predict that the enzyme will work at its best at 37c because that

Enzymes are biological catalysts that speed up chemical reactions, without being used up or changed. Catalase is a globular protein molecule that is found in all living cells. A globular protein is a protein with its molecules curled up into a 'ball' shape. All enzymes have an active site. This is where another molecule(s) can bind with the enzyme. This molecule is known as the substrate. When the substrate binds with the enzyme, a product is produced. Enzymes are specific to their substrate, because the shape of their active site will only fit the shape of their substrate. It is said that the substrate is complimentary to their substrate.

Hypothesis: I believe the rate of reaction will speed up as the temperature increases until it reaches about 37oC, which is the body temperature, where it will begin to slow down and stop reacting. I believe this will occur because enzymes have a temperature range at which they work best in and once the temperature goes out of this range the enzyme will stop working.

Introduction: Starting out with some background information, I know that enzymes are biological catalysts. The enzyme that I used for this experiment was potato juice. Enzymes make reaction rates go faster. They lower activation energy, making chemical reactions. Temperature has an effect on canola cultivars. The higher temperature decreased stem diameter, but room temperature had thicker stems. So I believe the same will happen for the catechol oxidase; the solution will react faster at room temperature. Other enzymes can also have different effects such as the enzyme in cattle serum. The enzyme lost activity in room temperature. With that being said room temperature can also be detrimental with specific enzymes. Fungus also

These results show how temperature of extreme high, or low affects enzyme activity. The highest rate of enzyme activity occurred at 37 Cº. Anything that was hotter or cold than 37 Cº slowed the reaction rate. As I thought, 100 degrees would denature the enzyme, and that was the case. The data provided shows exactly what temperatures enzymes work best, and worst. The objective was achieved as we discovered the different reaction rates under different temperatures. The results are reliable, as we know enzymes do not work well when under extreme heat or denaturation occurs. What I learned in this experiment was that enzymes don’t work well under cold temperatures because they tend to move slower. My hypothesis did not quite match, because I thought they work best at lower temperatures.

Background and Introduction: Enzymes are proteins that process substrates, which is the chemical molecule that enzymes work on to make products. Enzyme purpose is to increase the rate of activity and speed up chemical reaction in a form of biological catalysts. The enzymes specialize in lowering the activation energy to start the process. Enzymes are very specific in their process, each substrate is designed to fit with a specific substrate and the enzyme and substrate link at the active site. The binding of a substrate to the active site of an enzyme is a very specific interaction. Active sites are clefts or grooves on the surface of an enzyme, usually composed of amino acids from different parts of the polypeptide chain that are brought together in the tertiary structure of the folded protein. Substrates initially bind to the active site by noncovalent interactions, including hydrogen bonds, ionic bonds, and hydrophobic interactions. Once a substrate is bound to the active site of an enzyme, multiple mechanisms can accelerate its conversion to the product of the reaction. But sometimes, these enzymes fail or succeed to increase the rate of action because of various factors that limit the action. These factors can be known as temperature, acidity levels (pH), enzyme and/or substrate concentration, etc. In this experiment, it will be tested how much of an effect

B. Catalysis occurs on a specific site on the enzyme (the active site). The active site is usually less than 5% of the surface area of the protein, and is always in a cleft. The rest of the molecule serves to present the active site in a three dimensional structure that is capable of binding substrate and catalyzing the reaction. Binding to a substrate is very specific, and involves ionic interactions, H bonds and van der Waals forces.

There were three test tubes in which the experiment was held. A relatively equal sized portion of raw potato (this contained the enzyme [a biological catalyst] hydrogen peroxidase) was placed in each tube. Then, enough water to cover the potato was added. Proceeding this, each of the test tubes were assigned a temperature; cold, room temperature or warm (this was written on the tag so that they were not confused). The test tube destinated ‘cold’ was placed in a ice bath for five minutes. At the same time, the ‘hot’ test tube was placed in a hot water bath for five minutes. Meanwhile, the room temperature test tube sat at room temperature for five minutes. When the five minutes were over, the test tubes were returned to the rack (so that they were able to be observed). Then, the test tubes were allowed to sit at room temperature for five more minutes. Once that period of time was over, 2 ml of hydrogen peroxide (the substrate) was added to each tube.

Enzymes have an active site which has a complimentary base to a specific substrate, when these bind an enzyme-substrate complex is

enable the substrate to bind to the enzyme and form the enzyme substrate complex and

The purpose of this experiment is to learn the effects of a certain enzyme (Peroxidase) concentration, to figure out the temperature and pH effects on Peroxidase activity and the effect of an inhibitor. The procedure includes using pH5, H202, Enzyme Extract, and Guaiacol and calibrating a spectrophotometer to determine the effect of enzyme concentration. As the experiment continues, the same reagents are used with the spectrophotometer to determine the temperature and pH effects on Peroxidase activity. Lastly, to determine the effect of an inhibitor on Peroxidase, an inhibitor is added to the extract. It was found that an increase in enzyme concentration also caused an increase in the reaction rate. The reaction rate of peroxidase increases at 40oC. Peroxidase performed the best under pH5 and declined as it became more basic. The inhibitor (Hydroxy-lamine) caused a decline in the reaction rate. The significance of this experiment is to find the optimal living conditions for Peroxidase. This enzyme is vital because it gets rid of hydrogen peroxide, which is toxic to living environments.

Abstract: Enzymes, catalytic proteins that at as catalysis which makes the process of chemical reactions more easily. There are two main factors that actually affects enzymes and their functions which are temperature and pH. Throughout this experiment, the study how pH and peroxidase affects each other and the enzyme was made. The recordings of how the enzymes responded when it was exposed to four different pH levels to come up with an optimum pH which was predicted in the hypothesis and the IRV at the end.

“Enzymes are proteins that have catalytic functions” [1], “that speed up or slow down reactions”[2], “indispensable to maintenance and activity of life”[1]. They are each very specific, and will only work when a particular substrate fits in their active site. An active site is “a region on the surface of an enzyme where the substrate binds, and where the reaction occurs”[2].