In what tubes did you detect the presence of fatty acids?

Im stumped on these 4 questions too!!!!

I'm assuming you're referring to activity 4: Assessing Fat Digestion by Pancreatic Lipase and the Action of Bile.

Here's the answer I found pertaining to this:

Tube 1 investigated the action of bile on enzyme activity, and tube 2 examined lipase activity without bile. Bile enhances fat digestion by lipase. In tube 6, the pH would drop below pH 9.0. A small amount of fat digestion occurred because pH decreased from 9.0 to 8.97.

The optimim pH for lipase activity was pH 7.0. Using a pH method to assay for activity at pH 2.0 does not work because the buffer is already quite acidic. There could have been activity at pH 2.0 that was not detectable by this method.

In theory, lipase would be active in the mouth because its pH optimum is relatively neutral. However, it would not be active in the stomach because of the acidic pH condition. The substrate is vegetable oil (fat). The subunit formed is fatty acid (and monoglycerides).

I think the activity is from PhysioEx 8.0 on the Chemical and physical Processes of Digestion...based on Activity 4