Digestive System Lab Report: Key Findings and Observations

BioLab 3 Digestive System Lab Report Name, date, course and section required for password: Name : Palak Kapoor Date : 02/05/2024 Course and Section Number : BIOL-1409-72201 The lab report is unique each semester and checks have been put into place to ensure students are doing their own work. Copying from other students or from outside sources will result in a zero on the accompanying lab quiz. Human Digestive System 1. Which enzyme is secreted by the salivary glands into the mouth to begin chemical digestion? What food is digested by this enzyme? Salivary amylase and it begins the digestion of complex carbs into simpler sugars. 2. What is the purpose of bile? Used in the small intestine to emulsify lipids and fats into smaller particles. 3. Why does the stomach contain deep folds? What are they called? It helps increase the surface area available in the stomach, they are called rugae. 4. What is the function of the pancreas? Secretes enzymes into the duodenum that digest carbs, fats, proteins and nucleic acids. Villi 1. In 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. © 2024 Access Learning Systems SP24-B 1

2. What is the function of the lymph vessel within a villus? Capillary vessels carry blood toward the villus. 3. What is the difference between villi and microvilli? Villi- fingerlike projections lined with a simple columnar epithelial layer. Microvilli- thread like projections. 4. In Lab Section II, Exercise 2, identify the structures labeled A, B, C, D, and E of the human gastrointestinal tract. A - Hard Palate B - Epiglottis C - Liver D - Gallbladder E - Large Intestine © 2024 Access Learning Systems SP24-B 2

Fetal Pig Digestive System 1. In Lab Section III, Exercise 3, what is the difference between the hard and soft palate? The hard palate is white in color and looks like bone material while the soft palate is pink in color and looks like muscle material. 2. What is the difference between the glottis and the epiglottis? The glottis can be identified by the presence of small white cartilaginous flap and the epiglottis covers the glottis during swallowing to prevent food from entering the respiratory tract. 3. Where is the stomach located? The stomach has been lifted and the small intestince moved down to view the pancreas. 4. What role do the sphincters play in digestion? The pyloric sphincter is a band of smooth muscle at the junction between the pylorus of the stomach and duodenum of the small intestine Digestion 1. In Lab Section IV, Exercise 4, why did the solution in test tube 2 have two distinct layers? Missing of 0.5% bile 2. In Lab Section IV, Exercise 5, record observations of color changes observed in test tubes one through four at 30 minutes. Tube 0 min. 10 min. 20 min. 30 min. 1 Blue Red Red Red 2 Blue Red Red Red 3 Blue Blue Blue Blue 4 Blue Blue Blue Blue 3. What was the source of lipase in the experiment? Fat 4. What happens to the pH of a solution as fats are broken down? It increases the acidity. 5. In Lab Section IV, Exercise 6, what color indicates a positive test for starch? The temperature increases, reaction increases. But the reaction will be denatured at one point of temperature. © 2024 Access Learning Systems SP24-B 3

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6. In Lab Section IV, Exercise 7, record the rate of starch digestion for each test tube. Test Tube Temperatur e No. of Wells Tested Before Color Change x 30 Sec Elapsed Time (seconds) A 5c 19 x 30 570 B 23c 3 x 30 90 C 37c 2 x 30 60 D 60c 12 x 30 360 E 80c No color change x 30 0 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 it with this lab report. 8. Discuss the results shown in your graph. There is an optimal temperature for digestion to occur. It is only possible during room temperature and body temperature. © 2024 Access Learning Systems SP24-B 4

9. Describe the function of salivary amylase in digestion. Salivary amylase begins the digestive process by breaking down starch when you chew your food, converting it into maltose, a smaller carbohydrate. © 2024 Access Learning Systems SP24-B 5

Summary Questions 1. What is the function of the capillaries in a villus? Lymph vessel are creates to pick up the fluid that leaks into tissue from your bloodstream. 2. What is the difference between the cardiac sphincter and pyloric sphincter? Describe the location and function of each. The cardiac sphincter is a thin ring of muscle that keeps the contents of the stomach from coming back up into the esophagus. The pyloric sphincter prevents the contents of the duodenum from going back into the stomach. 3. What sort of digestion occurs in the mouth? Mechanical digestion: crush, grind. 4. Describe the processes that occur in the small intestine. This is the place where the food can be absorbed for nutrients, it is considered as chemical digestion. 5. Where is the pharynx and what is its function? The pharynx starts behind the nose and goes past the back of the mouth, down the neck and behind the larynx. The pharynx functions as a passageway for air and food, provides a resonating chamber for speech sounds, and houses the tonsils. Participates in immunological reaction against foreign invaders. 6. Is the appendix a vital organ? Where is it found in the human body? The appendix is not a vital organ , but it plays an important role in the body. Your appendix is in the lower right section of your abdomen. 7. What are enzymes? Explain how they function in degradation reactions. Enzymes are chemical catalysts in the body. They aid chemical reactions in our bodies. Degradation reactions are when a substrate is broken down into products where it needs enzymes to occur the reactions. 8. What was the purpose of the litmus solution in the fat digestion experiment? When combined with the fat source it serves as a color indicator from blue to pink. 9. How did you determine when starch digestion was complete? © 2024 Access Learning Systems SP24-B 6

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When the mixing turns yellow. 10. Compare average human body temperature to the optimum temperature of salivary amylase. They have the same temperature due to enzymatic reaction of salivary Amylase that work well from 27 degrees to 37 degrees . So salivary amylase has the optimum temperature with the human body. © 2024 Access Learning Systems SP24-B 7

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