Assignment:
I. Human Digestive System
1. Which enzyme is secreted into the mouth to begin chemical digestion? What food is digested by this enzyme?
2. What is the purpose of bile?
3. Why does the stomach contain deep folds? What are they called?
4. What is the function of the pancreas?
II. Villi
1. Based on Lab, Section II, Exercise 1, draw and label a villus using the following terms: venule, capillary, lymph vessel, arteriole, and simple columnar epithelium. Sign, date and prepare an image of your drawing and include it with this lab report.
2. What is the function of the lymph vessel within a villus?
3. What is the difference between villi and microvilli?
4. Based on Lab, Section II, Exercise 2, in one or two paragraphs, describe the journey of food through numerous specialized cavities as it enters the gastrointestinal tract, is broken down, absorbed and eliminated from the body.
III. Fetal Pig Digestive System
1. Based on Lab, Section III, Exercise 3, what is the difference between the hard and soft palate?
2. What is the difference between the glottis and the epiglottis?
3. Where is the stomach located?
4. What role do the sphincters play in digestion?
IV. Digestion
1. Based on Lab, Section IV, Exercise 4, why did the solution in test tube 2 have two distinct layers?
2. Based on Lab, Section IV, Exercise 5, record observations of color changes observed in test tubes one through four at 30 minutes.
3. What was the source of lipase in the experiment?
4. What happens to the pH of a solution as fats are broken down?
5. Based on Lab, Section IV, Exercise 6, describe the effect of temperature on the enzymatic reaction.
6. Based on Lab, Section IV, Exercise 7 record the rate of starch digestion for each test tube.
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Test Tube
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Temperature
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No. of Wells Tested Before Color Change
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x 30 Sec
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Elapsed Time (seconds)
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A
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x 30
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B
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x 30
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C
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x 30
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D
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x 30
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E
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x 30
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7. Using the data above, prepare a graph of elapsed time (Y-axis) for each temperature (X-axis). Sign and date your graph and submit with this lab report.
8. Discuss the results shown in your graph.
9. Describe the function of salivary amylase in digestion.
Summary Questions
1. What is the function of the capillaries in a villus?
2. What is the difference between the cardiac sphincter and pyloric sphincter? Describe the location and function of each.
3. What sort of digestion occurs in the mouth?
4. Describe the processes that occur in the small intestine.
5. Where is the pharynx and what is its function?
6. Is the appendix a vital organ? Where is it found in the human body?
7. Name three characteristics of enzymes and explain how they function in degradation reactions.
8. What was the purpose of the litmus solution in the fat digestion experiment?
9. How did you determine when starch digestion was complete?
10. Compare average human body temperature to the optimum temperature of salivary amylase.