Question

enzyme-enhanced reaction

ph of solution	temperature of solution (°c)	relative enzyme activity (%)
6	15	65
7	20	100
8	25	55
9	30	23

a student investigated the effect of temperature and ph on an enzyme - enhanced reaction. the results did not match what was expected. which statement correctly explains why the cause of the change in the enzyme activity cannot be determined?
a. two variables were changed at the same time, producing conflict in the data.

b. the enzyme functioned the same under different conditions.

c. the concentration of the enzyme increased with changing conditions.

d. the optimum enzyme activity resulted when the temperature changed the ph.

Explanation:

To determine why the cause of the change in enzyme activity can't be identified, we analyze the experimental design. In a valid experiment, only one independent variable should be changed at a time. Here, as the pH of the solution changes (from 5 to 9), the temperature of the solution also changes (from 10°C to 30°C). This means two variables (pH and temperature) are being altered simultaneously. When multiple variables are changed, it's impossible to tell which one is responsible for the change in the dependent variable (enzyme activity).

• Option B is incorrect because the enzyme activity (relative enzyme activity %) clearly changes (8, 65, 100, 55, 23) under different conditions, so the enzyme does not function the same.
• Option C is incorrect as there's no information in the table or problem statement indicating that enzyme concentration increased with changing conditions.
• Option D is incorrect because the data shows the optimum activity at pH 7 and 20°C, and there's no indication that temperature changes the pH in a way that causes optimum activity; rather, the issue is the simultaneous change of two variables.

So, the correct reason is that two variables were changed at the same time, producing conflict in the data.

Answer:

A. Two variables were changed at the same time, producing conflict in the data.