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Journal 8

The Flow of Energy
To solve the problem below, you must write a clear and convincing justification for accepting one of the possible answer choices as the best or most appropriate and for rejecting each of the other choices as less appropriate. Your reasons for rejecting choices are just as important as your reasons for choosing the best answer.
A biologist prepared a strip of agar (a gelatin-like substance) as shown in the figure below. At position 7, he placed a concentrated sample of amino acid A and at position 1, a concentrated sample of enzyme E. E is known to catalyze the conversion of A to a product P. Assume that A and E can diffuse through agar and that smaller molecules can diffuse much more rapidly than larger molecules. At what position would you most likely first find P?
1
 8
2
 7
3
 2
4
 4
5
 5
A biologist conducting an experiment on cell respiration was studying the combination of two chemical reactants to form a single product. This reaction was catalyzed by an enzyme. As she increased the temperaturem the speed of the reaction increased, until a certain temperature was reached. If the temperature was raised further, the speed of the reaction decreased rapidly. Which of the following is the best conclusion to be drawn from these results?
1
 As temperature is increased, the reactants move more rapidly.
2
 As temperature is increased, the products move more rapidly.
3
 Above a certain temperature, the enzyme combines better with the reactants.
4
 Above a certain temperature, the enzyme begins to move.
5
 Above a certain temperature, the shape of the enzyme is changed drastically, overcoming the direct effects of temperature on the reaction rate.