Background & Objectives: Digestive enzymes are present throughout the digestive system and are used to breakdown various macromolecules obtained from food. An enzymes activity is dependent upon the temperature and pH at which it is present. Enzymes work optimally at specific temperature and pH levels. The purpose of this lab is to examine various enzymes to determine which substrates they digest, and at which pH they work optimally.
Methods: The enzymes amylase, pepsin, and trypsin were each mixed with the substrates starch and albumin at pH levels of 2, 7, and 9. At 10 min intervals, the starch mixtures were treated with lugol’s solution and the albumin mixtures with biuret and ninhydrin solutions to determine whether digestion occurred. An unknown enzyme was then added to starch and albumin at the various pH and the same tests were performed to determine the identity of the unknown enzyme.
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Amylase at pH 2 showed presence of starch, whereas at pH levels 7 and 9 revealed absence of starch. The biuret test indicated undigested protein for all enzymes – except for the pepsin solution at pH 2 at 30 minutes contained short polypeptides. The ninhydrin test with amylase at pH 2 showed absence of amino acids, and their presence at pH 7 and 9. For pepsin, tests showed presence of amino acids, conversely trypsin had no amino acids present. The unknown exhibited similar results to trypsin – with the exception of the ninhydrin
During these experimental procedures, the implication of multiple different temperatures on fungal and bacterial amylase was studied. In order to conduct this experiment, there were four different temperatures used. The four temperatures used were the following: 0 degrees Celsius, 25 degrees Celsius, 55 degrees Celsius, and 80 degrees Celsius - Each temperature for one fungal and one bacterial amylase. Drops of iodine were then placed in order to measure the effectiveness of the enzyme. This method is produced as the starch test. The enzyme was tested over the course of ten minutes to determine if starch hydrolysis stemmed. An effective enzyme would indicate a color variation between blue/black to a more yellowish color towards the end of the time intervals, whereas a not so effective enzyme would produce little to no change in color variation. According to the experiment, both the fungal amylase and bacterial amylase exhibited a optimal temperature. This was discovered by observing during which temperature and time period produced a yellow-like color the quickest. Amylase shared a similar optimal temperature of 55 degrees Celsius. Most of the amylases underwent changes at different points, but some enzymes displayed no effectiveness at all. Both amylases displayed this inactivity at 0 degrees Celsius. At 80 Celsius both the enzymes became denatured due to the high temperatures. In culmination, both fungal and bacterial amylase presented a array of change during it’s
enzymes that will be used during this lab to test the ability of amylase to break down starch ,a
This experiment consisted of setting up a control group of starch in various temperature and then placing both fungal amylases and bacterial amylases in a mixture of starch and placing the solution of amylase and starch in various temperatures of water. After a certain amount of time- different amount of time needs to be used in order to have reliable results- iodine is added in a well on spot plates, then two drops of the mixture of amylase-starch is added from each temperature used, by adding iodine into the plates the mixture will show how much starch was hydrolyzed, this is used to calculate the amount of
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 part II of the lab six small glass tubes were obtained in a test tube rack. Ten drops of distilled water were then added to test tube 1, five drops to tubes 2-4, and no drops in tubes 5 and 6. Five drops of 0.1M HCl were added to test tube 5 and five drops of 0.1M NaOH to test tube 6. Five drops of enzyme were then added to all tubes except tube 1. Tube 3 was then placed in the ice bucket and tube 4 was placed in the hot bucket at 80-900C for five minutes, the remaining tubes were left in the test tube rack. After the five minutes five drops of 1% starch was added to every tube and left to sit for ten minutes. After ten minutes five drops of DNSA were then added to all the tubes. All the tubes were then taken and placed in the
The purpose of this experiment was to determine (1) the reaction rate of an amylase enzyme in starch and (2) the environmental factors that can affect the enzymatic activity. The hypothesis, in relation to the enzymatic activity by variables such as the substrate concentrations, temperature, PH and chemical interactions on the rate of reaction, stated
This was surprising due to our prior tests indicating that Enzyme B was an amylase and our inquiry of Enzyme A being neither of the two enzymes. Because we understand that enzymes contain R groups that are consisted of amine groups, and that the three enzymes are partially pure, we decided to conduct the extra experiment of the enzymes themselves in order to test for unusual levels of free amino acids within the enzymes. Our results display that there was a higher abundance of free amino acids in Enzyme B, which would affect the results in the Ninhydrin test that was conducted with the protein and protease
Hypothesis: If we decrease the level of pH in the enzyme Amylase, it will not be able to denature the carbohydrates in the potato starch solution after 10 drops because enzymes are very sensitive to pH levels and lowering it too much will compromise its ability to break them down.
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
test the pH of the amylase a drop of the solution should be put on pH
According to the results presented in table 2 above, digestion occurred in tube 1 and 3 as indicated by their color change from blue to bright orange. The orange color indicates that there was a moderate amount of sugar present in the solutions of tubes 1 and 3. Digestion occurred in tube 1 because it contained both the starch substrate and the pancreatic amylase. Digestion should not have occurred in tube 3 because while it did contain the enzyme, it did not contain the substrate. However, the pancreatic amylase could have reacted with the distilled water present in the tube.
The purpose of the experiment was to determine whether fluctuations of pH in the small intestine will have an effect on the enzymatic activity of trypsin. Our hypothesis stated that trypsin activity will be affected by changes in pH. Before the experiment, we predicted that the enzyme will function less effectively as the pH of the environment deviates from its optimal range, which is between 7.8 and 8.7. Trypsin activity will be the highest at its optimal range, and decreases as the pH becomes higher or lower than this range. Results from the experiment show that the rate of reaction between trypsin and the substrate BAPA follows a generally increasing trend as the pH of the TRIS buffer solution increases. At pH’s 4-6, the reaction
Difference enzymes work better under different conditions. Where in a human body might it be beneficial to have enzymes work in very acidic environments?
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
Amylase is an enzyme that is in human’s saliva as well as the pancreas. Enzymes are biological catalysts that speed up a chemical reaction. They break down complex molecules into simple ones. In this case, amylase converts starches (complex molecule) into simple sugars. That is why foods like potatoes for example, may taste sweet to us, because they contain starch. The optimum pH for pancreatic amylase is the pH of 7. In the experiment I have used buffer solutions with the pHs of 2.8, 4 and 6.5. I have also used iodine and starch. Normally, iodine is orange-yellow, however when you add starch to it, the solution will turn blue-black.