The Harcourt Essen Experiment Essay

The more acidic a substance is the less oxygen it will produce when going through a chemical reaction. During the Lab “How Do Changes in pH Levels Affect Enzymes Activity”, the researcher conducted an experiment to test the effects that an acidic, neutral, and a base substance will have when combine it with hydrogen peroxide. The data table shows that HCL (acidic substance) barley produced any oxygen at all when it was combining with Hydrogen Peroxide. The pH level for HCL was 2.5; this level indicates that the substance was very acidic. When the H2O and NaOH were tested they produced more bubbles than HCL. NaoH produced a little more bubbles than HCL. The pH that NaoH produced was a 9, which is a base. H2O produced more bubbles than both substances;

The preparation for the experiment started by gathering the solutions of enzyme Peroxidase, substrate hydrogen peroxide, the indicator guaiacol and distilled water. Two small spectrometer tubes and three large test tubes with numbered labels. In addition, one test tube rack, one pipet pump and a box of kimwipes were also gathered. Before the experiment, the spectrometer must be set up to use by flipping the power switch to on. Following, the machine was warmed up for 10 minutes and the filter lever was moved to the left. In addition, I set the wavelength to 500 nm with the wavelength control knob. Before the experiment, I had to create the blank solution by pipetting 0.1 ml of guaiacol, 1.0 ml of turnip extract and 8.9 ml water into tube #1. Following the creation of the blank, a control 2% solution was created.

Sulfuric acid - was used to stop the reaction with catalase and hydrogen peroxide. It denatured the enzyme (catalase) and halted the reaction so the amount of hydrogen peroxide decomposed could be measured.

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.

The purpose of this experiment was to simply measure oxygen production rates released from decomposed hydrogen peroxide under different conditions (concentration of enzymes, temperature, and PH level).

The control portion of a petri dish was used but we did not test to see if reacted with the hydrogen peroxide, so there was technically no control in this case.

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.

Figure one depicts the reaction rate of peroxidase enzyme over time. The y-axis shows the absorbance of the assay solutions, and the x-axis depicts time it took for the reaction to occur in seconds.

Purpose: The purpose of this experiment is to observe a variety of chemical reactions and to identify patterns in the conversion of reactants into products.

Peroxidase is an enzyme that breaks down hydrogen peroxide in our cells (Bansal et. al., 2016). Peroxidase is essential in life because hydrogen peroxide can cause damage to the cell. Hydrogen peroxide is the substrate to the peroxidase enzyme, where it binds to the active site and is broken down into water. In order to monitor the breakdown of hydrogen peroxide, the colorless dye guaiacol binds to the peroxidase and becomes oxidized as hydrogen peroxide is reduced to water, which then turns brown. Hydroxylamine is an inhibitor that has a similar structure to hydrogen peroxide. When hydroxylamine binds to the active site of peroxidase, it inhibits hydrogen peroxide from binding, thus preventing the breakdown of hydrogen peroxide (Lab Handout,

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.

This experiment will measure the rate of oxidation of iodide ions by persulphate ions to derive the rate law for the reaction. Starch will be added to the reaction to facilitate the measure of time during the reaction. The reactant solutions will contain (NH4)2SO4 and KI, represented as:

The presence of catalyst will cause hydrogen peroxide to break down into water and oxygen. The increase in the pH of the substrate will cause the increase in the rate of reaction. It will optimize at pH 7 and will diminish/moderate after pH 9.

4) Try and propose a mechanism for the reaction using the orders of reaction taking into account the iodine, propanone and sulphuric acid.

(6.2)Material and Methods in the process or exercise of measuring the starch we were used the following material and how we used them to conduct the experiment. Obtain seven tubes the material to be tested table 6.1 and then add seven to ten drops of iodine to each tube, and then record the color of the tubes contents in table 6.1