Because bile contains salts and digestive compounds and lipase is a digestive enzyme, you might create a simple qualitative experiment to test the action of bile and lipase. Bile is first used to emulsify and break down food entering the small intestine, and lipase is used afterwards by the pancreas to break down fats. With this information, I suggest this experiment:
1) Label 4 test tubes A, B, C, and D. Divide the fat solution equally into the 4 tubes.
2) In tube B, add an x amount (but not the whole volume) of the bile solution.
3) in tube C, add a y amount (but not the whole volume) of lipase solution.
4) in tube D, add the x amount of bile and the y amount of lipase solution.
5) Swirl/mix until everything looks homogenized/settled.
6) tube A is your control. Compare the 3 other tubes to it and write observations. You should be able to make conclusions about the role of bile in digesting a fatty solution, and the extent of digestion with and without the additional lipase.
Hope this is helpful!~ There are certainly many other possible experiments.
