Lab Report Enzyme

The results of the three-part experiment provide a deeper knowledge about the factors that influence the rate of the reaction of the enzyme activity and how the factors influence the structure or function of the enzyme.

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;

We increased the substrate, catechol, while maintaining the enzyme, catecholase, at the same volume. We came to the hypothesis that if the substrate was increased, then the rate of reaction would increase as long as there is enzymes to react with. The third experiment involved how temperature would affect enzyme activity. This was done by placing certain vials in certain temperatures and then analyzing the data in the spectrophotometer. We came to the hypothesis that if the temperature was increased, then the reaction rate would increase until it reaches the optimal temperature after that the reaction rate would decrease. This is because the enzyme will start to denature if the temperatures get too high or too low. The fourth experiment deals with how pH affects enzyme activity. For this experiment different vials with catecholase and different pH’s were observed under a spectrophotometer to see how the enzyme would be affected. We found our hypothesis to be, if pH is raised, then the reaction rate will increase until it reaches the optimal pH. The reaction rate will increase until the optimal pH because after the optimal pH, the enzyme will start to denature and not function as it

1. We measured 2 mL of diluted hydrogen peroxide (the substrate), 1 mL of guaiacol (the product indicator), and 1 mL of neutral buffer (pH 7) with a syringe and disposed it into tubes 1, 2 , 4, 9, 11, and 12.

In the initial part of the experiment, the materials used were: cuvettes, broad-range pH paper, dry watch glass, a spectrophotometer, parafilm, transfer pipette, solution E (solution B and distilled water), sodium carbonate, hydrochloric acid, and solution D (enzyme ALP high concentration). The experiment was initiated by preparing solution E. Solution E was formed by adding 6.5 mL of distilled water (dH20) with 6.5 mL of solution B (para nitro phenolphosphate - pNPP). A total of four cuvettes were labeled control 1, acidic 2, neutral 3, and 4 basic (Wilson, et al 2015). Each cuvette contains a specific pH with the exception of the control cuvette as shown in Table

Purpose of the Lab: In this lab I learned the different effects of substrates concentrations have on catalase activity. Introduction: Before you get started on this we should touch base on some critical points, these will help you perform and understand the experiment. Enzymes are protein molecules that are found in every living cell.

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

After the substrate solution was added, five drops of the enzyme were quickly placed in tubes 3, 4 and 5. There were no drops of enzyme added in tubes 1 and 2 and in tube 6 ten drops were added. Once the enzyme solution has been added the tubes were then left to incubate for ten minutes and after five drops of DNSA solution were added to tubes 1 to 6. The tubes were then placed in a hot block at 80-90oC for five minutes. They were then taken out after the five minute period and using a 5 ml pipette, 5 ml of distilled water were added to the 6 tubes and mixed by inversion. Once everything was complete the 6 tubes were then taken to the Milton Roy Company Spectronic 21 and the absorbance of each tube was tested.

To begin the experiment, six 16 x 150 mm test tubes were chosen, three marked “enzyme” and three marked “substrate.” For the baseline test using a 10 mL syringe and two 5 mL syringes, 7 mL of distilled water, 0.2 mL of a 0.3% guaiacol solution, and 0.3 mL of 0.1% hydrogen peroxide were added to the first substrate tube, containing a total volume of 7.5 mL. The baseline substrate test tube was then covered with a piece of Parafilm and gently mixed. To the baseline enzyme test tube, 1.5 mL of the standard 25g/400 mL concentration of peroxidase and 6.0 mL of distilled water were added; a piece of Parafilm also covered the tube then the test tube was gently mixed. The other two substrate tubes, one for the low concentration test and one for the

“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].

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 first experiment begun by filling a 600-ml beaker, almost to the top, with water. Next, a 10-ml graduated cylinder was filled to the top with water. Once water was added to the beaker and graduated cylinder, a thumb was placed over the top of the graduated cylinder. This would ensure that no water was let out and no bubbles were let into the graduated cylinder. Next, it was turned upside down and fully submerged into the beaker. Then, a U-shaped glass tube was attained. The short end of the glass tube was placed into the beaker with the tip inside of the graduated cylinder. Next, a 50-ml Erlenmeyer flask was received. After, 10-ml of substrate concentration and 10-ml of catalase/buffer solution were placed into the flask. A rubber stopper was then placed on the opening of the flask. After adding these, the flask was held at the neck and spun softly

An Enzyme is a protein, which is capable of starting a chemical reaction, which involves the formation or breakage of chemical bonds. A substrate is the surface or material on or from which an organism lives, grows, or obtains its nourishment. In this case it is hydrogen peroxide. This lab report will be explaining the experiment held to understand the effects of the changes in the amount of substrate on the enzyme’s reaction.

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

The independent variable in this investigation is pH. Each individual enzyme has it’s own pH characteristic. This is because the hydrogen and ionic bonds between –NH2 and –COOH groups of the polypeptides that make up the enzyme, fix the exact arrangement of the active site of an enzyme. It is crucial to be aware of how even small changes in the