Biology:   Bean Juice Amylase Inquiry Lab updated


Problem: What is bean juice amylase? What affects the efficiency of bean amylase? 

Provided Materials:

small beakers, plastic syringes, hot plate, distilled water, dropper bottles with Lugol's solution (I2KI), 1M Hydrochloric Acid- located on the front table, bean juice (water that dried beans soaked in overnight), starch solution  (see teacher for any other materials you might need).


a) I2KI  CANNOT be heated, hot I2KI can release a gas that irritates the lungs.

b) I2KI  contains iodine, students allergic to iodine should not handle I2KI .



Basic Procedure (teacher demo):

1.  Measure out 10 ml of the starch solution with the assigned syringe and place in a beaker.

2.  Add 3 drops of IKI to the beaker.  Note color change in your journal.

3.  Fill a different syringe with bean juice.  Add one drop at a time of bean juice to the starch-IKI solution until the solution clears.  Note how many milliliters it takes to clear the solution. 

Class discussion:

What did you observe during exploration?

What is puzzling about your observations?

What questions are raised?

What is the central causal question?

What are some possible explanations (hypotheses)?

How might these explanations be tested?

What are the expected/predicted results of each explanation and planned test?

1) What is bean juice amylase?

2)  What are the properties of bean juice amylase?

3) What can affect the effectiveness (efficiency) of bean juice amylase.

Lab Group:  (In your journals)

1) Using the basic procedure, come up with at least testable question and a control setup.  Identify your independent variable (IV), your dependent variable (DV), and your standardized variables (SV).

2)  Design your procedure (remember you must wear goggles to protect your eyes and include clean up procedures).

3) Design a data table to record your data (how will you measure your data, what units will you use?)

4) Design a graph for your data.


Do the lab, gather the data.

Questions to consider while running your experiment:

Following your test, what are your observed results?

How do your observed and expected results compare?

If observed and expected results do not match, is the mismatch attributable to a faulty hypothesis, a faulty test, a faulty deduction, or some combination? Can you tell? Why or why not?

If observed and expected results match, what conclusion should you draw? Have your results eliminated the alternatives? If not, what additional tests are needed?

Can you be sure that the match or mismatch of observed and expected results is not attributable to chance? If not, what can you do to reduce the likelihood of drawing an incorrect conclusion?

Class share out of data.  

1)Take notes on other teams' results.

2) Do the results make sense in light of your experiment?

3) If your team's results are dubious, you can repeat the experiment at lunch, after school, or A period if you don't have a class.

Typed Lab Write up:   (25 points)  (remember to avoid all pronouns even if there are pronouns in the following questions).
Title (must include the IV and DV of your testable question)  (1 point)
Purpose:  what was your testable question? (1 point)
Materials: list the materials used in your experiment  (1 points)
Procedure: Summarize your procedure. (2 points)
a)  Data Table  ( Figure 1: full title, columns labelled including units)  (4 points)
b) Graph (Figure 2: full title, axes labelled with units)  (4 points)  (pick the type of graph that will best represent your lab group's experiment, you can do an XY scatter graph (don't forget the trendline and equations). If appropriate you can do a Bar Graph, there are several ways, by hand on graph paper, or use Create a Graph  or you can use Excel to create your bar graph (2 points extra credit for degree of difficulty) How to do a Bar Graph in Excel 2007.

Conclusion:  10 points
 short findings paragraph "power conclusion", please include the following questions in the part 4 of the power conclusion.:

 How can adding acid to the starch solution affect the amount of bean juice amylase used to change the color from blue to clear?

What happened to the enzyme when the acid was added in regards to its shape/active site? 

Relate the changes in shape and active site to the four levels of protein structure including types of bonding. ( cite sources)

 What overall conclusion can you make about bean juice amylase? 

How is bean juice amylase related to the salivary and pancreatic amylase? (cite sources).

References: 2 points
 citations use APA format (APA:
don't forget to cite this lab.