Question

question 4.
graph with ph axis (5.0, 5.8, 6.6, 7.4, 8.2, 9.0) and vertical axis (0–10, labeled “pc”)
which of the following conclusions is supported by the data?
a. ○ the enzyme’s activity continually increases as ph increases from 5.0 to 9
b. ○ the optimum ph of the enzyme is 6.6
c. ○ the optimum ph of the enzyme is 5.8
d. ○ the enzyme’s activity is greater around ph 8.0 than around ph 5.0

Explanation:

• Option A: The graph shows a bar (or data representation) where the enzyme's activity (y - axis, "Pc" with values 0 - 10) doesn't show a continual increase. The bars seem to be at the same height (activity) from pH 5.0 to 9.0? Wait, no, maybe the graph is a bar graph with pH on x - axis (5.0, 5.8, 6.6, 7.4, 8.2, 9.0) and activity (Pc) on y - axis (0 - 10). If the activity is at the top (10) for all these pH values? Wait, no, maybe the dot is at the end. Wait, re - examining: The x - axis is pH (5.0, 5.8, 6.6, 7.4, 8.2, 9.0), y - axis is "Pc" (0 - 10). The graph has a rectangle from pH 5.0 to 9.0, with the top right corner (at pH 9.0) marked. But maybe the activity (Pc) is constant? Wait, no, the options:
• Option B: Optimum pH is the pH where enzyme activity is highest. If the activity is the same across pH 5.0 - 9.0, then 6.6 is not an optimum (since activity is same everywhere). So B is wrong.
• Option C: Similarly, 5.8 is not an optimum as activity is same across the range. So C is wrong.
• Option D: At pH 5.0, the activity is at the same level as at pH 8.0? Wait, no, maybe the graph is a line or bar where the activity (Pc) is 10 (max) from pH 5.0 to 9.0? Wait, no, maybe the y - axis is "enzyme activity" (Pc) and the graph shows that from pH 5.0 to 9.0, the activity is constant (since the bar is a rectangle). But then, the activity at pH 8.0 is equal to that at pH 5.0? Wait, no, maybe I misinterpret. Wait, the options: Let's think again. If the enzyme's activity (Pc) is 10 (the top of the y - axis) for all pH from 5.0 to 9.0, but maybe the graph is a bit different. Wait, the key is to analyze each option:
• Option A: "Continually increases" – but if the activity is constant (same height) from 5.0 to 9.0, then it's not increasing. So A is wrong.
• Option B: Optimum pH is 6.6 – but if activity is same at all pH, there's no single optimum. But maybe the graph is a bar graph where the activity is highest at all these pH? No, maybe the graph is a line where the activity (Pc) is 10 (max) and the dot is at pH 9.0. Wait, maybe the y - axis is "enzyme activity" and the graph shows that from pH 5.0 to 9.0, the activity is 10 (so constant). But then, at pH 8.0, the activity is 10, and at pH 5.0, it's also 10? No, that can't be. Wait, maybe the graph is a bit unclear, but let's check the options again.
• Option D: "The enzyme’s activity is greater around pH 8.0 than around pH 5.0" – if the activity (Pc) is 10 at pH 8.0 and maybe lower at pH 5.0? Wait, maybe the graph is a bar graph where the height (activity) is 10 from pH 5.0 to 9.0, but that would mean activity is same. But maybe the original graph (not fully visible) has the activity (Pc) as 10 (max) at pH 8.0 and maybe lower at pH 5.0. Alternatively, maybe the x - axis is pH, and the y - axis is enzyme activity, and the data shows that at pH 8.0, the activity is higher than at pH 5.0. Among the options, D is the only one that can be supported. Because A says "continually increases" – but if the activity is flat (same) from 5.0 to 9.0, it's not increasing. B and C say optimum pH is 6.6 or 5.8, but if activity is same across the range, there's no optimum at those points. So D is correct as the activity at pH 8.0 (around 8.0) is greater (or equal, but among the options, D is the best) than at pH 5.0.

Answer:

D. The enzyme’s activity is greater around pH 8.0 than around pH 5.0