Three different digestive fluids are placed in test tubes The fluid placed in test tube #1 was extracted from the mouth. The fluids in test tubes #2 and #3 were extracted from what was believed to be the stomach. 5 mL of olive oil are placed in each of the test tubes, along with a pH indicator. The intial colour of the solutions is red, indicating the prescence of a slightly basic solution. The solution in test tube #3 turns clear after 10 min, but all the other test tubes remain red. Describe the conclusions you could draw from the experiment.
Justify each of the conclusions with the data provided.
(Hint: Consider which substances were digested. What are the structual components?)
Olive oil is a mixture of fatty acid triglycerides with a very high content of oleic acid esters. Olive oil and other oils are not water soluble so their acidity cannot be measured in terms of pH. The initial color of the solutions of tube # 1 depends of acidity saliva. Typically the acidity of a mixed human saliva is 6,8-7,4 pH, but at high speed reaches salivation 7,8 pH, that indicate presence of a slightly basic solution. The intial colour of tubes #2 and #3 is a very strange fact. The normal acidity of the empty stomach is 1.5-2.0 pH. There are 2 assumptions in this case. First one, those fluids in test tubes #2 and #3 were extracted from human with low acidity of stomach. Low acidity is observed in case of hypoacid gastritis or gastroduodenitis, and gastric cancer. Second one, the fluids in test tubes #2 and #3 were extracted from the intestines, but not from the stomach. The acidity of the fluids of the small intestine is 7.2-7.5. or 8.6 pH. The solution in test tube #3 turns clear after 10 min, because fluids in this solution have a lipase. This enzyme breaks down triglycerides to fat acids, glycerin, mono- and biglycerides. This components have a neutral pH. This is a case of solution in test tube #3 clearing.