AccelePrep for the ACT Test 2nd Edition Student Text

C HAPTER 10 | F AST T RACK TO S CIENCE M ECHANICS • 187

4. Which of the following experimental designs would test the hypothesis that enzyme concentration can affect the rate of starch digestion? F. Using the same pH, temperature, and enzyme levels in all beakers, test additional samples at 90 minutes, 120 minutes, and 240 minutes. G. Using different pH, temperature, and enzyme levels in all beakers, test additional samples at 90 minutes, 120 minutes, and 240 minutes. H. Using the same pH and temperatures in all beakers, test additional samples with the enzyme at one-half the strength, two times the strength, and four times the strength. J. Using the same pH, temperature, and enzyme levels in all beakers, test additional samples after stirring for 3 minutes, 9 minutes, 15 minutes, and 60 minutes. 5. On the basis of the results of Experiment 1, what would probably occur if Experiment 2 were carried out at a pH level of 5? A. Digestion of starch to sugar would slowly begin in the beakers containing crackers plus water. B. Overall, digestion of starch to sugar would ’”‘„ƒ„Ž› –ƒ‡ ’Žƒ…‡ Ž‡•• ‡ˆϐ‹…‹‡–Ž›Ǥ C. Overall, digestion of starch to sugar would ’”‘„ƒ„Ž› –ƒ‡ ’Žƒ…‡ ‘”‡ ‡ˆϐ‹…‹‡–Ž›Ǥ D. The experimental results would not change.

1. The ingredient used as a control for both experiments is the: A. cracker. B. water. C. enzyme. D. starch/sugar level. 2. Which of the following hypotheses is supported by the results of Experiment 1? F. At the appropriate pH level, water can break down starch, but at a slower rate than salivary amylase can. G. After any given time interval, no differences in the effects of the three buffers on salivary amylase activity should be detectable. H. Salivary amylase can show activity at each of the three pH levels tested. J. The duration of time in which starch and enzyme remain in the beakers should have no effect on the amount of sugar produced. 3. Under what conditions does salivary amylase appear to work best? A. Any pH level greater than 5 and any temperature greater than 25°C B. Any pH level greater than 5 and any temperature less than 45°C C. pH level of 9 and temperature equals 37°C D. pH level of 7 and temperature equals 37°C