Question

“-” represents a clear/yellow solution, “+” represents a light blue solution, and “++” represents a dark blue solution.

1. 1% glucose - observation: negative. Starch not present

2. 1% starch - observation: ++. Starch present

3. 1% starch + amylase #1 (body temperature). Observation: negative. Starch not present

4. 1% starch + amylase #2 (body temperature). Observation: negative. Starch not present.

5. 1% starch + amylase #1 (high temp). Observation: +. Starch present

6. 1% starch + amylase #2 (high temp). Observation: +. Starch present

7. 1% starch + amylase #1 (acidic pH). Observation: +. Starch present

8. 1% starch + amylase #2 ( acidic pH). Observation - . Starch not present

dh MY LASE ACTIVITY (POSTLAB) EXPERIMENT EIGHT 1. Which sampl e is the positive control and which sample is the negative control? Explain. 2. After incubating amples labeled-amylase #1 at 35-40°C, was the amylase active or inactive in the s and "amylase W2"? Explain how you determined if they were active or inactive. 3. After incubating at 100°C, was the amylase and "amylase #2"? Explain how you determined if they were active or inactive. active or inactive in the samples labelled "amylase #1 . pare the amylase activity of your samples after incubating at body temperature (test tubes 3/4) and temperatures (test tubes 5/6). Based on your results, what can you conclude regarding the 4. Com at higher effect of temperature on the activity of the enzyme? Does this match what was discussed in lecture? 5. After incubating at an acidic pH, was the amylase active or inactive in the samples labelled "amylase "amylase #2"? Explain how you determined if they were active or inactive. Compare the amylase activity of your samples after incubating at neutral pH (test tubes 3/4) and at acidic pH (test tubes 7/8). Based on your results, what can you conclude regarding the effect of pH on the activity of the enzyme? Does this match what we discussed in lecture? EXPERIMENT EIGHT 1. Which sample is the positive control and which sample is the negative control? Explain. 2. After incubating at 35 and -40°C, was the amylase active or inactive in the samples labelled "amylase #1 . -amylase #27 Explain how you determined if they were active or inactive. 3 After incubating at 100°C, was the amylase active or inactive in the samples labelled "amylase #1 and "amylase #2"? Explain how you determined if they were active or inactive. Compare the amylase activity of your samples after incubating at body temperature (test tubes 3/4) and at higher temperatures (test tubes 5/6). Based on your results, what can you conclude regarding the effect of temperature on the activity of the enzyme? Does this match what was discussed in lecture? 4. 5. After incubating at an acidic pH, was the amylase active or inactive in the samples labelled "amylase #1" and "amylase #2"? Explain how you determined if they were active or inactive. Compare the amylase activity of your samples after incubating at neutral pH (test tubes 3/4) and at acidic pH (test tubes 7/8). Based on your results, what can you conclude regarding the effect of pH on the activity of the enzyme? Does this match what we discussed in lecture? 64

Answer 1

1.  1% glucose - observation: negative. is positive control. Since a positive control is one that shows response to amylase degradation.  1% starch - observation: ++. starch present is a negative control. since it responds negatively to amylase degradation.

2. With amylase #1 and amylase #2 at 35- 40^oC  there is no starch present. amylase enzyme cuts the starch molecule into glucose, maltose, maltotriose, and some oligoglucoses. hence solution does not respond to starch test. hence both amylase #1 and amylase #2 are active.

3. After incubating the reaction mixture at 100^oC both solutions (Test tube 5 and Test tube 6) show a positive test for starch. This can be owed to denaturation of amylase enzyme. since the amylase enzyme is denatured it will not degrade the starch. thus reaction shows starch positive.

However, there is a slightly blue color instead of dark blue. this can be due to two reasons. Firstly, not all enzymes are denatured i.e. few enzymes are still active. Secondly, since the solution is at high-temperature hydrolysis of starch molecule might have taken place.

4. Based on the results of test tube 3/4 and test tube 5/6 we can conclude that with an increase in temperature the enzyme activity is decreasing.

5. In test tube 7 starch was not degraded. hence we can conclude that amylase #1 is inactive at acidic pH. In the test tube number 8 starch was degraded hence enzyme amylase #2 is active in acidic pH.

6. Based on a comparative study of test tube 3/4 and 7/8 we conclude that amylase #1 is active at body temperature and inactive at acidic pH. amylase #2 is active in body temperature as well as in acidic pH