Abstract Lactose is recognised as a disaccharide; in other words, it consists of glucose and galactose and two smaller sugars bound altogether with a covalent bond. In the form described, lactose is indigestible by us humans; therefore it must be hydrolysed, or broken down, for our body in order to process it. Lactase catalyses this process by decreasing the energy required for hydrolysis to happen. Lactase is a digestive enzyme that catalyses the breakdown of lactose, a sugar found in milk. Lactase works well within a limited range of both pH and temperature in its environment, thus making it dependent on both elements for it to complete this essential reaction. If lactase is seen as non-functional because of temperature or pH extremes, the …show more content…
As they get older, milk is not as important a part of their diet. Many people no longer make lactase as they get older. They then have trouble digesting dairy products. The lactase enzyme they can no longer produce for themselves can be added to dairy products before they eat them. That is why it was easy to buy lactase for the experiment. Introduction In this experiment, a substrate (lactose in cow milk) is used to test the enzyme lactase. The objective is to identify the effect of pH and Temperature on lactase. Thereafter, by plotting the results on graphs and finding their standard deviation, I would be able to interpret the distribution of the data and would find the optimum pH or temperature based on the data. Hypothesis Since human body is of the most efficient and the most accurate among species, I would assume that lactase works at its best while at body temperature: around 37o C. Also, since the human blood pH is regulated to stay within the narrow range of 7.35 to 7.45, I assume that the optimum pH for lactase activity is at that range of pH. Although some people suffer from lactose intolerance, that does not mean that their body cannot provide the optimum pH and Temperature for lactase to function, but it means lactase is in either in short supply or not …show more content…
In test tube D add two millilitres of the sucrose solution and one millilitre of enzyme solution. 10. Repeat step 4. 11. In test tube E add two millilitres of the sucrose solution and one millilitre of water. 12. Repeat steps 4. Data Collection and Graphs: The uncertainty values for glucose is ±50 mg/dL because it was printed on the test tape container. Table 1. Demonstrating the amount of glucose in each test tube Temperatures Test Tube 1 ±50 test tube 2 ±50 Test tube 3 ±50 25oC 550 500 500 37oC 650 700 650 0.8oC 300 350 350 100oC 0 0 50 Positive glucose Control, 25oC 900 900 850 Table 2. Demonstrating the amount of glucose in each test tube Optimal pH The pH scale, ranging from 0 to 14, is used to determine the extent to which a solution is acidic or basic. Solutions that register as a 7 are considered neutral. Those below are considered acidic while those above are deemed basic. The optimal pH for lactase performance is around 6, but lactase can function in an acidic environment ranging between a pH of 2 to 7, which corresponds to the typical pH of the human small intestine. Deviations in pH outside of this range, particularly to the high basic levels of 10 to 12, can cause the lactase enzymes to become
of sugar to 25ml of water and dissolve it. When we have the water at
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
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
C) Again, rinse the saucepan and then add 250 grams of sugar to your 250ml graduated cylinder and then add water up to the 250ml mark. You will place a small piece of plastic wrap over the top of the graduated cylinder (or parafilm if you have that), and mix the sugar with the water. Then pour the contents into a small saucepan over the stove. You will fill the graduated cylinder up to the 250ml mark again and then pour the tap water into the saucepan as well. You will now heat the mixture on the stove and stir until the sugar has dissolved. Once this has happened, you will remove the solution from the saucepan, pour the solution into a container and label that container 50% sugar solution.
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
• Dilute some of the enzyme stock with buffer A to make a 4 mg/ml solution.
3. Specifically state where in the intestine sucrase is likely to be most active (pH along GI tract).
Lactose Intolerance Lactose intolerance is the inability to digest significant amounts of lactose, the predominant sugar of milk. This inability results from a shortage of the enzyme lactase, which is normally produced by the cells that line the small intestine. Lactase breaks down milk sugar into simpler forms that can then be absorbed into the bloodstream. When there is not enough lactase to digest the amount of lactose consumed, the results, although not usually dangerous, may be very distressing. While not all persons deficient in lactase have symptoms, those who do are considered to be lactose intolerant.
Using the graduated cylinder, measure 20mLs of the stock sucrose solution and 180mL of water to create a 3% sucrose solution and place it into the 250mL beaker (beaker #2). Place bags #1‐3 (red, blue, yellow) into beaker 2 and bag #4 (green) into beaker 1. Allow the bags to sit for one hour. After allowing the bags to sit for one hour, remove them from the beakers carefully open the bags, noting that often times the tops may need to be cut as they tend to dry out. Measure the solution volumes of each dialysis bag using the empty 250 ml beaker.
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.
11. It is then repeated for the solution of unknown concentration (A, B or C).
There were several steps completed to prepare for the experiment. Three dialysis tubes were filled with approximately the same volume of distilled water and then were tied shut. The initial mass (in grams) of the tubes was taken using a triple beam scale. I then filled three 500 mL beakers with 400 mL of water each and dissolved different masses of solute (table sugar) in each beaker in order to make 5%, 10%, and 20% solutions. The beakers were labeled accordingly, and then 20 g, 40 g, and 80 g (respectively) of table sugar was weighed out using a digital scale and placed into the corresponding beakers. The sugar was stirred in using a stirring rod until all of the solute was completely dissolved.
2. Fill a flask with pure water (0% sugar), another with 0.2M water, another flask with 0.4 M water, and another flask with 0.8M water.
“Lactase is an enzyme that breaks down lactose, the sugar in milk. It is produced by the cells lining of the small intestine. Most people are born producing it, but often make less of it as they age, which causes lactose intolerance the symptoms for this include nausea, bloating, and diarrhea to name a few. This enzyme is produced
2cm of a solution was tested and added 2 cm of 10% of potassium hydroxide solution and the test tube was shaked.