Representing and Describing Data · with figure
An enzyme is tested at different pH values while temperature and substrate concentration are held constant. Which interpretation is best supported? Use Figure 1 to answer the question.
- AThe data show that pH is the dependent variable.
- BThe enzyme has the same activity at all pH values.
- CThe highest shown rate is at pH 6correct
- DThe enzyme must be permanently destroyed at pH 4 and pH 8 in every organism.
Why C is correct
The reaction rate is highest at pH 6 among the tested values. The data support a pH optimum near pH 6 under the stated conditions, but they do not prove permanent destruction at other pH values.
The evidence in the prompt matters before the topic label: "An enzyme is tested at different pH values while temperature and substrate concentration are held constant. Which...". The supported answer is "enzyme shows the highest tested reaction rate at pH 6" because The reaction rate is highest at pH 6 among the tested values. Distractors such as data show that pH is the dependent variable or enzyme has the same activity at all pH values either ignore the stated pattern or name a related concept without matching the evidence.
Representing and Describing Data · with figure
An enzyme is tested with and without an inhibitor. Substrate concentration is increased until reaction rate plateaus. Which interpretation is best supported? Use Figure 1 to answer the question.
- AThe inhibitor increases the maximum reaction rate.
- BVmax decreases while the shown half-maximal concentration stays the samecorrect
- CThe inhibitor prevents the enzyme from binding any substrate at all because half-maximal concentration changes.
- DThe inhibitor converts the enzyme into a nucleic acid.
Why B is correct
Figure 1 shows the same substrate concentration at half-maximal rate but a lower maximum reaction rate with inhibitor. This pattern is consistent with an inhibitor that reduces catalytic capacity rather than simply changing the shown binding-related value.
The evidence in the prompt matters before the topic label: "An enzyme is tested with and without an inhibitor. Substrate concentration is increased until reaction rate...". The supported answer is "inhibitor lowers maximum reaction rate without changing the shown..." because Figure 1 shows the same substrate concentration at half-maximal rate but a lower maximum reaction rate with inhibitor. Distractors such as inhibitor increases the maximum reaction rate or inhibitor prevents the enzyme from binding any substrate at all... either ignore the stated pattern or name a related concept without matching the evidence.