The Effect of pH on the Digestion of Casein by Trypsin
When planning the experiment, the equipment and method had to be well thought-out in order for the experiment to be accurate and efficient.
Firstly, I have chose to use a 1% trypsin concentration then altered it to 0.8%, because a higher concentration means more trypsin molecules in the solution and therefore more enzyme substrate complexes are likely to occur with the casein in the milk, causing digestion of the casein to be faster. However, I don’t wantowever digestion to occur too quickly as I will not be able to analyse the effect of PH. Therefore, I chose a lower concentration which would allow me to test the percentage transmission at
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In addition, PH is the independent variable I am testing; therefore, its constancy is important.
Variables in the experiment will need to be controlled and the following need to be kept constant
* Concentration of trypsin
* Amounts of reagents
* Enzyme to substrate ratio
* Temperature
* Method of measuring solutions
I will use equal amounts of trypsin, milk, PH, buffer and distilled water in all the experiments and will use the same measuring equipment to ensure fair representation of the effect of different PH on digestion. If variables aren’t adequately controlled then the data collected would be erroneous and would not represent the true effects of PH on digestion as altering variables could lead to changes in rate of reaction.
As we know the collision theory states that the more collisions in a system, the more likely the molecules will react and therefore the faster the reaction. Rates of reaction can be affected by variables such as concentration, as more molecules of the substance are present therefore increasing the chance of a collision, another is temperature.
All enzymes have an optimum temperature at which they work the fastest, this is because more kinetic energy is available and particles move faster resulting in more collisions and hence more
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 practical was carried out to investigate the effect of pH on the reaction of the enzyme acid phosphatase.
Given the background, we hypothesized that for the first experiment, the lactase will break down lactose in milk and have a similar effect to sucrose. We also predicted that the Milk + Lactase reactant would have more glucose, the Milk + Water reactant would have a little bit of glucose broken down, the Sucrose + Lactase reactant would have less glucose than the Milk + Water reactant, and the Sucrose + Water reactant would have little to no glucose at all. As for the first procedure of the second experiment, we had hypothesized the more basic the solution would become, then the more glucose there would be. Our prediction for the first procedure of the second experiment was that there would be no glucose found in the solutions containing pH 4 and pH 7. For the second procedure of the second experiment, our hypothesis was that glucose would be present in the reactants at 4ºC and 25ºC while the reactant that had been in the hot water bath at 100ºC would have little to no glucose because it would have evaporated. We predicted that for this temperature experiment, the glucose would evaporate at 100ºC and would remain at 4ºC and 25ºC. For the first experiment we had found that a reactant of Milk + Lactase have high levels of glucose, while the other three reactants do not. As for the second experiment, for the first procedure, amounts of glucose were found in
-VariablesoIndependent:The temperature of the milkoDependent:The time taken for the milk to solidifyoControlled:The same amount and type of milk usedThe same amount and concentration of enzyme mixture usedThe same test tube sizeResults:-TableAmount of enzyme mixture (mL)Amount of milk (mL)Temperature (oC)Time for milk to clot (min)Ex: 1 Ex: 2 Average2.551060+60+60+2.552034.2036.0035.12.55303.554.203.882.55402.102.252.182.55505.004.454.73Discussion:The experiment showed that changing the temperature did affect the rate at which the milk solidified. At low temperatures of 10oC and 20oC the milk took the longest to solidify and at 10oC did not even go lumpy after an hour. As the temperature increased the speed at which it reacted got faster until it reached around 40oC where the speed began to drop.
PH can affect the way fermentation occurs due to the irregularity of the acidity or alkalinity within the glucose solution. This is an enzyme-based reaction that is susceptible to pH. The aim of this experiment was to determine how pH affects the yeast fermentation rate by performing the experiment numerous times with a different pH of glucose solution which included pH 3, 5, 7, 9, 11. The hypothesis was ‘If the pH is lower than the neutral point then the fermentation reaction will occur faster?’ The experiment conducted was to measure the amount of C02 produced by the yeast going into fermentation, however varying the pH of glucose solution by using different pHs . To test this every 5 minutes the volume of gas in the test tube was observed and recorded until a period of 30 minutes had been. The end results
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
These results shown from this experiment led us to conclude that enzymes work best at certain pH rates. For this particular enzyme, pH 7 worked best. When compared to high levels of pH, the lower levels worked better. The wrong level of pH can denature enzymes; therefore finding the right level is essential. The independent variable was the amount of pH, and the dependent being the rate of oxygen. The results are reliable as they are reinforced by the fact that enzymes typically work best at neutral pH
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.
Enzymes are proteins which can catalyse chemical reactions without changing themselves. The enzyme lipase breaks down the fat in dairy products such as full-cream milk for people who are lactose intolerant. Lipase acts on its specific substrate, lipids produces fatty acids. If enzyme concentration increases, random collisions between the substrates and active sites of enzyme increase due to the increasing amount of active sites which allow more collisions to happen, so the rate of breakdown of lipids to simpler substances will increase. During the experiment, sodium carbonate solution and pH indicator phenolphthalein will be added ahead of
10. Which had the greatest average 1- OD (amount of bile acid adsorbed to meal particles), the standard meal with bile acid or the
The hypothesis states that if the solution is hypotonic the results will decrease, if the solution is hypertonic the results will increase and if the solution is isotonic the solution will vary and or remain constant. In order to test the predictions of the hypotonic, hypertonic, and isotonic hypothesis for the solution made during the study, four samples of sucrose were taken and placed into two different beakers each containing a different concentration. Then dialysis tubing A was placed into beaker 1 with B, C, and D placed into beaker 2 for 45 minutes and weighted at 15 minute intervals. My finding in the study was that each of the four samples changed from their initial weight and for the most part accurately proved the hypothesis.
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 experiments involved PH buffers of different pH were added to potato juice, water, and the enzyme catecholase. The mixture was then subjected to spectrophotometer at a wavelength of 420nm taking the absorbance readings. In the second experiment, a phosphate buffer of PH 7.0 was used in different measures together with different measurement of potato juice and the enzyme catecholase then subjected to the spectrophotometer at a wavelength of 420nm. The data collected inform of table and analyzed using descriptive statistics such as line graph and later interpreted, showing that PH and enzyme concentration do affect the rate of enzyme reaction
To study the effects of temperature, pH, enzyme concentration, and substrate concentration there were certain steps that were followed in order to conduct this experiment. Each factor had a separate procedure to follow to find how each had a different effect on the enzyme.