Question

Table 2: Pancreatic Lipase Digestion of Triglycerides and the Action of Bile Tube No. 1 2 3 4 5 6 Additives Lipase Lipase Lipase Deionized water Lipase Lipase Vegetable oil Vegetable oil Deionized water Vegetable oil Vegetable oil Vegetable oil Bile salts Deionized water Bile salts Bile salts Bile salts Bile salts pH 7.0 buffer pH 7.0 buffer pH 9.0 buffer pH 7.0 buffer pH 2.0 buffer pH 9.0 buffer Incubation 37°C condition 60 minutes 37°C 37°C 60 minutes 37°C 60 minutes 37°C 60 minutes 37°C 60 minutes 60 minutes pH 6.21 6.72 9.00 7.00 2.00 8.97 0 Activity Questions: Use Table 2 above to answer the following questions. 1. Describe how lipase activity is measured in this experiment. How can you tell if a change in pH has occurred in each of the test tubes? 2. What is the purpose of test tubes 3 and 4? What type of controls are they? 3. Which tube has the highest lipase activity? How can you tell? 4. Compare test tubes 1 and 2. What is the difference between these tubes (looking at the additives), and why does tube 1 have higher lipase activity? 5. Using the results above, explain why pancreatic lipase would be active in both the mouth and the intestine.

Answer 1

1.- It is measured by a change in pH. Well, experimentally speaking you measure pH either by using a pH meter of any kind and inserting it into the samples.

2.- They precisle controls. They are negative controls, one of them does not have the enzyme (tube 4, lipase) and the other one does not have the substrate (tube 3, vegetable oil)

3.- Tube 1, and we know that because it is the tube that shows the greater change in pH from the initial values

4.- The difference is that tube one has vile salts and tube 2 does not (only water to complete the volume). This is expected because vile salts work as a protector for lipase, they prevent denaturation of lipase in the sample

5.- Well, both the mouth and the intestines have a favorable pH around 7 and a proper metabolical temperature around 37° C. The mouth does not provide an environment as good as the intestines does with the vile salts but still lipase will recieve proper temperature and pH values.