Abstract: Enzymes are biological catalysts. They are also proteins and there properties are determined by their structure. The reactant is a substrate and the resulting factor is the product. . Enzyme activity is influenced by many different things including: substrates, products, presence of cofactors, and inhibitors. The effect of inhibitors is measured as a percentage called percent inhibition. During this experiment we observed the change in enzyme concentration, the change in substrate concentration, temperature variation, and the effect of non-competitive and competitive inhibitors. This experiment helped us investigate the activity of the enzyme catechol oxidase in a potato. It also helped us have a better understanding of competitive …show more content…
In order to prepare the homogenate we had to cut up pieces of the potato to extract the enzyme. We then had to blend the potato to homogenize it. We used a standard house blender in order to do this. When you blend the pieces of potato it ruptures the cell membrane, the vesicles, and all of the other membrane bound organelles. By blending the potato it releases the enzyme and cofactors necessary for this lab. After the homogenate is prepared we had to put it in the centrifuge. A centrifuge is a machine that separates fluids of different densities. Centrifugation forces the insoluble particles to the bottom of the tube. The insoluble mass at the bottom of the tube is called the pellet. The rest of the solution is called the supernatant. In this experiment we used ortho-quinone, and because it has a brown tint to it we can measure it using a spectrophotometer. In this experiment you will also need to make several dilutions. In this experiment you will take one half of the previous solution and put it in the next tube. The first solution will be full strength, the second will be ½ strength, and so on to 1/8 strength. When doing this experiment start out with twice as much full strength. Instead of starting with 3mL start with 6mL. Transfer half of it to a second test tube and then dilute it with an equal amount of dilutent (water). Mix it thoroughly. The concentration of this solution will be half that of the full strength solution. The solution in the third tube will have half of the concentration in the second tube and ¼ the concentration of the full strength. Repeat this procedure until you reach 1/8. After we gathered all of the information we needed we had to use the reaction rate to calculate the amount of
This lab was performed in order to discover the activity of the enzyme catecholase in different pH levels as well as its absorbance in differently concentrated solutions. A spetrophotometer was used to measure the absorbance of the enzyme catecholase in different pH solutions as well as to measure the absorbance of catecholase in solutions with different concentrations of potato juice and phosphate buffers. Absorbance of the enzyme catecholase was at an optimum level when pH was close to neutral. When pH was acidic or basic, the catecholase was less effective. Also, when there was a higher concentration of potato juice and a lower concentration of phosphate buffer, absorbance of the enzyme increased.
The way this could’ve changed our results is the fact that the enzyme might have not been as prevalent in the potato as they would have been in the root of it. In the future one way to avoid such mistakes is to either choose a different method of inquiry or to extract the enzyme from the same place of each
Procedure: I used a ruler, thermometer, and scale to take measurements. I used a graduated cylinder, short step pipet, scale, and ruler to determine volume and density. I used a volumetric flask, graduated pipet, pipet bulb, scale, and glass beaker to determine concentrations and densities of various dilutions.
Catechol, in the presence of oxygen is oxidized by catechol oxidase to form benzoquinone (Harel et al., 1964). Bananas and potatoes contain catechol oxidase that acts on catechol which is initially colorless and converts it to brown (Harel et al., 1964). In this experiment, the effect of pH on the activity of catechol oxidase was conducted using buffers ranging from pH2 to pH10. Two trials were conducted due to the first trial results being altered by an external factor. The results were acquired by taking readings every 2 minutes for 20 minutes from a spectrophotometer and then recorded on to the table. The data collected in the table were then made into graphs to illustrate the influence of pH on the catechol oxidase catalyzed reaction. After analysis, the data revealed that pH did have a significant influence on the enzyme as recorded by absorbance per minute. However, the data was collected was not accurate due to external factors, thus the results are debatable and should be experimented again for validation.
The lab leaders and the Punk Rock Warlord prepared three different concentrations of catechol oxidase by extracting potato juice (because it contains lots of catechol oxidase). Pure catechol, a 5mL test tube, 1mL/5mL
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.
Procedure Part 1: Observe Normal Catalase Reaction Place a potato cube (3x3x3 cm) into a test tube Add 3 mL of H2O2 into each test tube Allow 1 minute for reaction to occur Record the height in cm of the bubbles Rate how rapidly the solution bubbles on a scale of 0-5 (0=no reaction, 1=slow,...5 =very fast) Part 2: Effect of Temperature on Enzyme Activity Label 3 test tubes: hot, cold, and room temperature Place potato cube (3x3x3 cm) into each test tube Place the test tube labeled hot and cold into the coordinating baths Place the test tube labeled room temperature into the test tube labeled room temperature on the test tube rack Level each test tube in place for 3 minutes After 3 minutes record the temperature of each tube Add 3 mL of H2O2 into each tube After a minute, record the height in cm of the bubbles in each tube Rate how rapidly the solution bubbles on a scale of 0-5 Part 3: Effect of pH of Enzyme Activity Label 3 test tubes acid, base, and pH 7 Place 3 mL of potato catalase into each tube Add 10 drops of vinegar to the test tube labeled acid Add 10 drops of ammonia into the tube labeled base Add 10 drops of distilled water into the tube labeled pH 7 After 2 minutes add 3 mL of H2O2 to each
The enzyme we used is catalase which is a common enzyme found in many organisms. Catalase breaks down hydrogen peroxide producing oxygen and water. For this experiment, we followed the protocols set out in Principles of Biology Laboratory Manual. In order to test the hypothesis, there were test tubes containing hydrogen peroxide incubated at different temperatures to understand the effects of temperature on enzyme activity. Test tubes containing potato pieces treated in different pH levels and Spec-20 were to understand effects of pH on enzyme activity.
Overall we are testing the enzyme activity by either heating or cooling liver to a specific temperature and mix it with peroxide, so we can see the difference by watching the
1st step is to label 3 test tubes A,B,C. 2 step is to put 3 mL of homogenate into test tube A and place in ice water for 30 minutes. 3rd step is to put 3 mL of homogenate into test tube B and set it at room temperature. 4th step is to put 3 mL of homogenate into test C and place in hot bath water. After, add hydrogen peroxide to each test tube and observe what
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
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
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
Biology 121 KS Lab Report IV 03/06/2018 Jannet Marin Testing the Effects of Temperature and pH on Potato Catalase Activity Introduction: To bear life in the cell, nearly all metabolic processes need enzymes. Enzymes are “macromolecular biological catalysts that help to speed up, or catalyze, chemical reactions.” The activity of enzymes is also affected by changes in the pH and temperatures. However, tremendously high or low pH and temperature values could cause complete loss of activity for most enzymes. Catalase is the most common enzyme found in potatoes and almost all organisms that are exposed to oxygen.
The differences for the rates of reaction between the liver and potato are accounted for because liver contains more catalase enzymes than potatoes. This is because the liver is responsible for ridding toxins out of the body and as a result needs more catalase enzymes to do so; explaining the bigger reaction it had with the hydrogen peroxide.