AP Bio Practice Essay – Biochemistry
Question
A class of biology students performed an experiment on the digestion of starch by
salivary amylase. Each student determined the length of time required for different
dilutions of his saliva to digest completely a standard concentration of starch. Iodine was
used to test for the presence of starch. The results obtained by some of the class are
summarized in the table below
Table 1: Time required for the disappearance of starch with various saliva dilutions
Dilutions of
saliva
Student A
Student B
Student C
10%
5%
2%
1%
45 sec
90 sec
260 sec
50 sec
100 sec
300 sec
100 sec
200 sec
600 sec
135 sec
270 sec
800 sec
a. Explain the biochemical background of the experiment
b. Present the data for student A, B, C in graphic form
c. Carefully examine the data collected by the three students above and state as
many conclusion as you can assuming that there have been no errors in technique