Homework # 5, Due 9/18/09

55- The drugs usually used to treat high blood pressure do not affect blood vessels in the lungs. Bosentan is a new drug being studied as a treatment for high blood pressure in the lungs. In an experiment, patients treated with bosentan showed an improvement in the distance they could walk without fatigue within 12 weeks. Design an experiment to test the effectiveness of bosentan as a drug to treat high blood pressure in the lungs. In your answer be sure to:

• state the hypothesis your experiment will test [1]
• state how the control group will be treated differently from the experimental group
[1]
• state two factors that must be kept the same in both the experimental and control
groups [1]
• state the type of data that should be collected to determine if the hypothesis is supported


Base your answers to questions 46 through 50 on the information and data table below and on your knowledge of biology.

The effect of temperature on the action of pepsin, a protein-digesting enzyme present in stomach fluid, was tested. In this investigation, 20 milliliters of stomach fluid and 10 grams of protein were placed in each of five test tubes. The tubes were then kept at different temperatures. After 24 hours, the contents of each tube were tested to determine
the amount of protein that had been digested. The results are


46 -The dependent variable in this investigation is the
(1) size of the test tube
(2) time of digestion
(3) amount of stomach fluid
(4) amount of protein digested

Directions (47–48): Using the information in the data table, construct a line graph on the grid on page 15, following the directions below.

47- Mark an appropriate scale on each axis. [1]
48- Plot the data on the grid. Surround each point with a small circle and connect the points.


49- If a sixth test tube identical to the other tubes was kept at a temperature of 30°C for
24 hours, the amount of protein digested would most likely be

(1) less than 1.0 gram
(2) between 1.0 and 4.0 grams
(3) between 4.0 and 9.0 grams
(4) more than 9.0 grams

50 -This investigation was repeated using 10 grams of starch instead of protein in each test
tube. The contents of each tube were tested to determine the amount of starch that
had been digested. The test results showed that no starch digestion occurred. Explain
why no starch was digested. [1]