PhysioEx 8 (Chemical and Physical Processes of Digestion) Review Sheet
Terms in this set (16)
List the substrate and the subunit product of amylase.
the substrate of amylase is animal starch and the product is maltose and glucose
What effect did boiling and freezing have on enzyme activity? Why?
the boiling denatured the enzyme and inactivated it as predicted. the freezing has no effect on the enzyme
At what pH was the amylase most active? Describe the significance of this result.
amylase was most active at pH 7.0 significant because this is the same pH as the mouth
Briefly describe the need for controls and give an example used in this activity.
controls are needed to validate the results of the experiment. tube 5 is an example where the enzyme that tests for contaminating glucose in the starch is absent
Describe the significance of using a 37degree C incubation temperature to test salivary amylase activity.
it is significant because it is the same temperature as body temperature so it should be ideal for the enzyme
Describe why the results in tube 1 and tube 2 are the same.
in tube 1 the amylase is hydrolyzing the starch to glucose and tube 2 the glucose is already present in the hydrolyzed form
Describe the result in tube 3.
should not be positive for the test because amylase should not digest cellulose
Describe the usual substrate for peptidase.
peptides and proteins
Explain how bacteria can aid in digestion.
by breaking down cellulose which we do not produce cellulase
Describe the effect that boiling had on pepsin and how you could tell that it had that effect.
it inactivated the pepsin. the fact that no activity was seen with tube 1 however it was very active in tube 2
Was your prediction correct about the optimal pH for pepsin activity? Discuss the psychological correlation behind your results.
the correct prediction is pH 2.0 this is because pepsin is most active at the pH of gastric juice which is about 2.0 pH
What do you think would happen if you reduced the incubation time to 30 minutes for tube 5?
it is possible that no digestion of protein would be seen since only a small amount is seen
Explain why you can't fully test the lipase activity in tube 5.
measurement of lipase activity uses a decrease in pH since the pH in tube 5 is already low, it is difficult to tell if fatty kids are released
Which tube had the highest lipase activity?
Tube 1 pH 7.0 which approximates the pH of the small intestine
Explain why pancreatic lipase would be active in both the mouth and the intestine.
since the activity of pancreatic lipase is highest at pH 7.0 the enzyme should be active in the mouth and the pancreas
Describe the process of bile emulsification of lipids and how it improves lipase activity.
bile serves to mechanically break up large globules of fat and produce small droplets that effectively increases the surface area of the lipids