Processes of Digestion - Review Sheet
ACTIVITY1 Assessing Starch Digestion by Salivary Amylase
1. List the substrate and the subunit product of amylase. _starch & maltose respectively__
2. What effect did boiling and freezing have on enzyme activity? Why? How well did the results compare with your prediction?__Boiling caused amylase to be denatured, thus inactivating the enzyme. Freezing has no effect. The function of an enzyme is directly related to its environment, like temperature.__
3. At what pH was the amylase most active? 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