Describe the significance of this result. __ pH 7. 0. Amylase is most active in neutral areas, such as the mouth and the small intestine (duodenum). __ 4. Briefly describe the need for controls and give an example used in this activity. __Controls are needed to validate the results of the experiment. One example is testing for sugar using Benedict’s test on Amylase The negative control was used to detect if amylase was contaminated with maltose or not. __ 5. Describe the significance of using a 37°C incubation temperature to test salivary amylase activity. __37°C simulates an environment of normal body temperature. __ A C T I V I T Y 2 Exploring Amylase Substrate Specificity 1. Describe why the results in tube 1 and tube 2 are the same. _In tube #1 the amylase is hydrolyzing the starch to glucose, & in tube #2 the glucose is already present in the hydrolyzed form. __ 2. Describe the result in tube 3. How well did the results compare with your prediction? _
Amylase cannot digest cellulose, so tube #3 is not positive for Benedict’s test. __ 3. Describe the usual substrate for peptidase. _A protein (BAPNA in this experiment). __ 4. Explain how bacteria can aid in digestion. Bacteria can aid in digestion by breaking down cellulose with the enzyme cellulase, humans do not produce this enzyme. _ A C T I V I T Y 3 Assessing Pepsin Digestion of Protein 1. Describe the effect that boiling had on pepsin and how you could tell that it had that effect. _Boiling denatured the enzyme. You can tell because the protein was not digested in tube #1. There was no color change & a density of 0. __ 2. Was your prediction correct about the optimal pH for pepsin activity? Discuss the physiological correlation behind your results. _Yes. The optimum pH matches the pH secreted by gastric glands.
Physioex9.0 Ex8 Essay Example
Gastric juice is also close to pH 2. ___ 3. What do you think would happen if you reduced the incubation time to 30 minutes for tube 5? _This would reduce digestion in tube 5. __ A C T I V I T Y 4 Assessing Lipase Digestion of Fat 1. Explain why you can’t fully test the lipase activity in tube 5. _Measurement of lipase activity uses a decrease in pH. Because the pH in Tube #5 is already very low, it is hard to tell if fatty acids are released. __ 2. Which tube had the highest lipase activity? How well did the results compare with your prediction?
Discuss possible reasons why it may or may not have matched. _Test tube #1 should have the highest activity because the pH is closest to that of the small intestine. __ 3. Explain why pancreatic lipase would be active in both the mouth and the intestine. _Pancreatic lipase is most active at pH 7. 0 The pH of the mouth is 7. 0 & the pH of the small intestine is close to 8. 0 so the enzyme would function in both places. ___ 4. Describe the process of bile emulsification of lipids and how it improves lipase activity. _Fat globules are separated into droplets by bile salts through an emulsification process which is physical not chemical, which promote lipase activity__