Physio Ex 9.0. Exercise 8 : Chemical and Physical Processes of Digestion?

Questions must be posted, not attached.

ACTIVITY 1:  Assessing Starch Digestion by Salivary Amylase   Answers
1.     List the substrate and the subunit product of     amylase    
2.   What effect did boiling and freezing have on enzyme activity? Why? How well did the results compare with your predictions?   
3.   At what pH was the amylase most active? Describe the significance of this result      
4.   Briefly describe the need for controls and give an example used in this activity   
5.   Describe the significance of using a 37ºC incubation temperature to test salivary amylase activity    
ACTIVITY 2:  Exploring Amylase Substate Specificity   
6.   Describe why the results in tube 1 and tube 2 are the same   .


7. Describe the result in tube 3. How well did the results compare with your prediction?   8. D
8.  Describe the usual substrate for peptidase   40

9.  Explain how bacteria can aid in digestion   
ACTIVITY 3:  Exploring Amylase Substate Specificity

   
10. Describe the effect that boiling had on pepsin and how you could tell that it had that effect
   
11. Was your prediction correct about the optimal pH for pepsin activity? Discuss the physiological correlation behind your results   
12. What do you think would happen if you reduced the incubation time to 30 minutes for tube 5?   

ACTIVITY 4:  Assessing Lipase Digestion of Fat
   
13. Explain why you can’t fully test the lipase activity in tube 5.   
14. Which tube had the highest lipase activity? How well did the results compare with your prediction? Discuss possible reasons why iy may or may not have matched   
15. Explain why pancreatic lipase would be active in both the mouth and the intestine   
16. Describe the process of bile emulsification of lipids and how it improves lipase activity.   

did anyone find an answer to this set?

1.Substrate : Starch ;  subunit : maltose
2. boiling denatures the enzyme non-functional and permanently changes it.  Freezing will slow down or stop the reaction, but can be reheated to be functional again.
3. pH 7.0 - this pH is found in areas where starch digestion occurs like the mouth and duodenum.
4. controls ensure that there is no contamination in the solutions.  Testing for sugar using Benedict's test on Amylase & D.I. water ensures that the D.I. water or Amylase was not contaminated with maltose.
5. 37 degrees simulates an environment similar to body temperature.

Thanks

Exercise 8, Activity 2, Question #1
Describe why the results in tube 1 and 2 are the same?
Tube 1 & 2 contained: Amylase, Starch pH 7.0 buffer. Incubation @ 37C for 60 min
Both tubes same results:  IKI test- negative, Benedict's Test- Positive  WHY??

Anybody have the answer to Activity 4's "which tube had the highest lipase activity" from above?

Thanks!!!!!

how bile improves lipase activity?

I've not received my activation email at this time, but I was hoping someone would be able to help me with some additional questions pertaining to this lab. Please see the questions and my answers, if you have additional feedback please feel free add to mine or correct me entirely.

In Activity 3:
A) What do you think would happen if you reduced the incubation time to 30mins?

- Decreasing the incubation time causes a decrease in optimal density.  (Please correct me if I am wrong, I am taking a stab in the dark at this one)

B) What do you think would happen if you decreased the incubation temp. to 10 degrees C?

-  There should be LESS digestion at lower temps, as digestion is most effcient at 37 degrees C (body temp.)


In Activity 4:

A) Can you determine if fat hydrolysis has occured in tube 5? What about tube 6?

Completely lost here as to how I can determine this, any help please and thank?

Big Thank you!! You're a life saver :scratch: :scratch:

Can someone help me with Activity 1 Review sheets?

1)   List the substrate and the subunit product of amylase.
Answer: The Substrate for amylase are starch (amylose and Amylopectin), glycogen, and various Oligosaccharides and the subunit is maltose.

2)   What effect did boiling and freezing have on enzyme activity? Why? How well did the results compare with your prediction?
Answer: I was correct with my prediction that boiling would stop enzyme activity, however I thought that freezing would have no effect but in fact it slows activity down.

3)   At what pH was the amylase most active? Describe the significance of this result.
Answer: It was most active at 7.0. This means that amylase needs a relatively high pH in order to be active or be seen.

4)   Briefly describe the need for controls and give an example used in this activity.
Answer: controls ensure that there is no contamination in the solutions.  Testing for sugar using Benedict's test on Amylase & D.I. water ensures that the D.I. water or Amylase was not contaminated with maltose.

5)   Describe the significance of using a 37C incubation temperature to test salivary amylase activity
Answer: This temperature simulates a temperature close to body temperature.