Design Experiment: Enzyme Inhibitors.
Research question: What is the effect of adding lead nitrate solution on the activity of amylase enzyme?
Aim: To test the effect of adding nitrate solution on the activity of amylase.
Background Information:
Inhibitors are molecules which repress or prevent another molecule from engaging in a reaction. They are substances that attach themselves onto an enzyme and reduce or prevent the enzyme’s ability to catalyse reactions. Competitive Inhibitors are inhibitors that occupy the active site of an enzyme or the binding Site of a receptor and prevent the normal substrate or ligand from binding. An active site is a region on the surface of an enzyme to which substrates bind and which catalyzes a chemical
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This is because a greater mass of lead nitrate reduces the ability of the amylase to breakdown starch into maltose. Therefore lead nitrate acts as a non-competitive inhibitor reducing the enzyme’s ability to catalyse the reaction. Lead nitrate is non-competitive because it affects the enzyme’s activity even though it is present in small quantities. The hypothesis were proven since the lead nitrate changes the shape of the active site of the enzyme and prevents some starch molecules from binding to the active site for catalysts. According to the results obtained from the experiment, my hypothesis is accepted and is correct. My hypothesis was, “There is an inverse relationship between the mass of lead nitrate and the ability of amylase to convert starch into maltose.” Despite the results obtained were correct and proved that the experiment was a success a few variables emerged during the performance of the experiment that if improved could result to a more accurate result. We didn’t have enough time to do this experiment over and over again so we didn’t have enough results to compare. Another important factor that may have influenced in our experiment was the quantity taken of the lead nitrate. We didn’t have any colorimeter so our result might not 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
Used to see if the temperature of the water is at 37oc – 40oc and if
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
Amylase experiment # 2 was done to see how the pH affected the efficacy of the enzyme. First we collected all of the materials that were necessary to make this experiment. We needed five clean test tubes, the following standard solutions, 1% Starch Solution pH 3,1% Starch Solution pH 5,1% Starch Solution pH 7,1% Starch Solution pH 9,1% Starch Solution pH 11
Inhibitors - As mentioned earlier, enzymes have an active site specific to the substrate molecules. However, it is possible for other molecules similar to enzyme's substrate to bind with the enzyme's active site and therefore, inhibit the enzyme's task.
Effect of pH on Enzyme Activity. 1. Dependent Variable. amount of product (glucose and fructose) produced 2. Independent Variable. pH 3. Controlled Variables. temperature; amount of substrate (sucrose) present; sucrase + sucrose incubation time
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.
The null hypothesis for the first experiment was that substrate concentration would have no effect on the reaction rate. It was hypothesized that the reaction rate would increase with rising substrate concentrations, until all active sites were bound. The null hypothesis for the second experiment was that temperature would not have an effect on reaction rates. It was hypothesized that until the enzyme is denatured, as temperature increased, so would the reaction rate.
8. The people who make up this article is the students from 7 different universities. It was rather representative because they were from universities that were located across the US, not just from one specific area. This was a unsystematic selection procedure because they weren’t from specific groups or students, just casual students from the seven different universities which created a representative sample of a big population.
An inhibitor is a substance that slows down or stops enzyme-substrate complexes forming. Competitive inhibitors have a similar shape to the substrate which allows them to enter the active site so the substrate cannot; therefore they both compete for the active site. If you add more substrate the effect of the competitive inhibitor will be reduced.
enzymes that will be used during this lab to test the ability of amylase to break down starch ,a
test the pH of the amylase a drop of the solution should be put on pH
For this experiment, we have to prepare our phosphorylase which extracted from a potato. We prepared by weighed about 250 grams of peeled potato and cut it into cubes. The extracts then blended with 100mL of 0.1M NaF. After filtered the contents into a clean 250mL centrifuge bottle, we centrifuged it for 3 minutes. Then, separated the supernatant into a centrifuge bottle, which is our phosphorylase preparation. The enzyme assay used in this experiment today is the iodine test. As the iodine reacts with starch, it will form a brown, blue or black precipitate due to the iodine ions forcing into a linear arrangement. The endpoint of the enzyme reaction indicates the presence of starch by using the iodine test to determine. The faster the endpoint is reached, the less active the phosphorylase is.
In the following experiments we will measure precise amounts of potato extract as well as Phenylthiourea, combined with or without deionized water and in some instances change the temperature and observe and record the reaction. We will also investigate the different levels of prepared pH on varying samples of the potato extract and the Phenylthiourea and record the results. We will answer question such as what is the best temperature for optimum temperature reaction as well as the best pH level for the same reaction.
The purpose of this experiment was to test the effects that temperature, pH, and substrate