First, we had to determine the appropriate concentration of enzyme to use for the single point assays in the remainder of the lab. In addition, we also calculated the extinction coefficient for the colored product. To determine the appropriate concentration of enzyme needed, 4 tubes were set up. The kinetic profiles of 4 tubes were observed and the appropriate enzyme concentration needed was determined to be 0.1ml. The absorbance readings of each tube are shown in the table 1a and 1b below. In addition, the absorbance values of each tube were plotted as a function of time. Four graphs were created for 4 tubes and the graphs are shown below. For tube 4, we made a mistake of not letting the reaction run long enough, so only the beginning part of the plateau was observed. In theory, when the absorbance of the product reaches a plateau, the velocity of the reaction is 0. …show more content…
The kinetic profile of tube 1 is represented by a horizontal line in graph 1. Tube 2 contained 0.01ml of enzyme and graph 2 represents the kinetic profile of tube 2. It shows that the absorbance of tube 2 increased over time at an exponential rate. The amount of enzyme added to tube 3 was 0.1ml. The absorbance of this tube increased at a steady rate over time. Graph 3 represents tube 3 and its enzyme kinetic profile is indicated by the positive linear line. About 0.5ml of enzyme was added to tube 4 and graph 4 represents its kinetic profile. The absorbance increased over time, but at the end it began to plateau. Comparing the kinetic profiles of 4 tubes, the appropriate enzyme concentration needed for the assay was determined to be
In this lab or experiment, the aim was to determine the following factors of enzymes: (1) the effects of enzymes concentration the catalytic rate or the rate of the reaction, (2) the effects of pH on a particular enzyme, an enzyme known and referred throughout this experiment as ALP (alkaline phosphate enzyme) and lastly (3) the effects of various temperatures on the reaction or catalytic rate. Throughout the experiment 8 separate cuvettes and tubes are mixed with various solutions (labeled as tables 1,3 & 4 in the apparatus/materials sections of the lab) and tested for the effects of the factors mentioned above (concentration, pH and temperature). The tubes labeled 1-4 are tested for pH with pH paper and by spectrophotometer, cuvettes 1a-4a was tested for concentration and cuvettes labeled 1b-4b was tested for temperature in four different atmospheric conditions (4ºC, 23ºC, 32ºC and 60ºC) to see how the enzyme solution was affected by the various conditions. After carrying out the procedures the results showed that the experiment followed the theory for the most part, which is that all the factors work best at its optimum level. So, the optimum pH that the enzymes reacted at was a pH of 7 (neutral), the optimum temperature that the reactions occurs with the enzymes is a temperature of 4ºC or
In the experiment we used Turnip, Hydrogen Peroxide, Distilled Water, and Guaiacol as my substances. On the first activity, Effect of Enzyme concentration of Reaction Rate for low enzyme concentration, we tested three concentrations of the turnip extract, and hydrogen peroxide. For the Turnip Extract I used 0.5 ml, 1.0 ml, and 2.0 ml. For hydrogen peroxide we used 0.1 ml, 0.2 ml, and 0.4 ml. We used a control to see the standard, and used a control for each enzyme concentration used. The control contains turnip extract and the color reagent, Guaiacol. We prepared my substrate tubes separately from the enzyme tubes. My substrate tube
The use of multiple test tubes and Parafilm was used for each experiment. Catechol, potato juice, pH 7 phosphate buffer, and stock potato extract 1:1 will be used to conduct the following experiments: temperature effect on enzyme activity, the effect of pH on enzyme action, the effect of enzyme concentration, and the effect of substrate concentration on enzyme activity. For the temperature effect on enzyme activity, three test tube were filled with three ml of pH 7 phosphate buffer and each test tube was labels 1.5 degrees Celsius, 20 °C, and 60 °C. The first test tube was placed in an ice-water bath, the second test tube was left at room temperature, and the third test tube was placed in approximately 60°C of warm water. After filling the test tubes with three ml of the
Enzymes are types of proteins that work as a substance to help speed up a chemical reaction (Madar & Windelspecht, 104). There are three factors that help enzyme activity increase in speed. The three factors that speed up the activity of enzymes are concentration, an increase in temperature, and a preferred pH environment. Whether or not the reaction continues to move forward is not up to the enzyme, instead the reaction is dependent on a reaction’s free energy. These enzymatic reactions have reactants referred to as substrates. Enzymes do much more than create substrates; enzymes actually work with the substrate in a reaction (Madar &Windelspecht, 106). For reactions in a cell it is
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.
To test the effect of pH on enzyme production rate, adhere to the following procedure: Set up three test tubes by labelling them as pH 4, pH 7, and pH 10, and putting them in a test tube rack. Add 3 milliliters (mL) of 3% H2O2 and 3 milliliters (mL) of the pH buffer to each test tube. Squirt 2 drops of the enzyme solution into the test tube labeled pH 4. Place the test tube stopper on the opening of the test
However, the rate of reaction only increases for a certain period of time until there is lesser substrate molecules than the enzyme molecules. The increase of enzyme concentration does not have effect if there are lesser substrate molecules than enzyme molecules initially.
The data supported Hypothesis 4 and the trend seemed to be linear. The results were obtained due to the fact that with an increase of concentration, there were more substrates in the substance, which led to more encounters with an enzyme in the allotted time. With a higher probability of finding an enzyme, the rate of reaction would be increase. There only seemed to be one point slightly out of place in Group A’s Procedure 4. The only source of error in this circumstance would be, as previously described, only due to the reaction time with the timer, and the exact depth the filter paper was released.
The purpose of this lab report is to investigate the effect of substrate concentration on enzyme activity as tested with the enzyme catalase and the substrate hydrogen peroxide at several concentrations to produce oxygen. It was assumed that an increase in hydrogen peroxide concentration would decrease the amount of time the paper circle with the enzyme catalase present on it, sowing an increase in enzyme activity. Therefore it can be hypothesised that there would be an effect on catalase activity from the increase in hydrogen peroxide concentration measured in time for the paper circle to ride to the top of the solution.
The main objective of this experiment was to determine how different factors, such as the type of enzyme and the temperatures that each of the enzymes were exposed to, could affect the rate of enzyme activity. In order to measure this, a potato enzyme and liver enzyme were placed in four different temperatures for 24 hours. Each enzyme was then placed in a test tube with hydrogen peroxide and the rate of enzyme activity was measured. The result was that the rate of enzyme activity decreased as the temperature increased for the liver enzyme, but increased for the potato enzyme.
An important aspect of studying proteins is understanding their properties. The hypothesis of this experiment aimed to test whether the enzyme in question, N-acetyl-β-D-Hexosaminidase, has an overall negative charge and will elute from the DEAE column in the first protein peak. The experiment was done in two parts. The absorbance values obtained from conducting the Lowry protein assay were used to extrapolate the total amount of protein and calculate the concentration of the protein. The total amount of protein in the sample was 120µg and the concentration of the protein was 24.0 µg/µl, which was within the allowed range of error. An enzyme assay with paranitrophenol was conducted to determine the specific activity of the enzyme. The specific activity of the isozyme HEX B was calculated to be 0.00009 units/mg and the specific activity of the isozyme HEX A was 0.00004 units/mg. At the conclusion of this experiment, the data obtained from the ion-exchange chromatography indicated that the unknown protein sample contained two isozymes of the enzyme N-acetyl-β-D-Hexosaminidase. It was observed that isozyme HEX A had an overall negative charge and therefore eluted last from the DEAE column, whereas HEX B had an overall positive charge and did not bind to the column, hence eluted first.
The experiment was carried out to investigate the effects of the increase in the enzyme concentration on the rate of reaction. By using self investigative and experimental skills, the experiment was done in order to determine how the rate of reaction will be altered, whether it will increase, decrease or remain constant when the different concentration of enzymes added.
The enzymatic activity was measured using the Apase substrate that changes color upon treatment and quantitated using the spectrophotometer. The highest absorbency thus denoted the optimal conditions for the experiment with regard to substrate level concentration, pH and temperature. In order to best compare the enzymatic activity, and determine the effect these variables had upon absorbency, the measurement of the reaction at specific times was necessitated. The substance NaOH was thus employed to effectively stop the reaction and permit these measurements to be
The rates of enzyme activity are affected by pH, temperature, presence of inhibitors, concentration of enzyme and substrate. Hence, if any of these variables is changed, the rate of enzyme activity would alter
A way of measuring how fast an enzyme works is by conducting an enzyme assay. An enzyme assay is the process by which a spectrophotometer is used to determine how the concentration of a colored substrate or product changes within an enzyme solution over time.1 With that being said, the purpose of this experiment is to perform multiple enzyme assays in order to determine the concentrations of unknown solutions and to gain an understanding of how different enzymes work.